HomeMy WebLinkAboutPermit L93-0031 - CITY OF TUKWILA - 40TH-42ND AVENUE SOUTH IMPROVEMENTS / ENVIRONMENTAL IMPACT STATEMENT (EIS)l93-0031
improvements to 42nd avenue south sepa
ENVIRONMENTAL IMPACT STATEMENT (EIS)
STATE OF WASHINGTON
DEPARTMENT OF ECOLOGY
P.O. Box 47600 • Olympia, Washington 98504 -7600 • (206) 407 -6000 • TDD Only (Hearing impaired) (206) 407 -6006
February 18, 1994
Mr. L. Rick Beeler
City of Tukwila
6300 Southcenter Blvd
Tukwila WA 98188
Dear Mr. Beeler:
We received the determination of nonsignificance for the road
improvements on 40th and 42nd Avenues South ( #L93- 0031).
Although there was no comment period, we have the following
comments.
The design and intent of the project should comply with the
Stormwater Management Manual for Puget Sound.
If you have any questions, please call Mr. Ron Devitt with our.
Water Quality Program at (206) 649 -7028.
Sincerely,
ea-
Rebecca J. Inman
Environmental Review Section
RI:
94 -0948
cc: Ron Devitt, NWRO
Janet Thompson, NWRO
RECEIVED
FEB 2 21994
COMMUNITY
DEVELOPMENT
CITY OF TUKWILA
DETERMINATION OF NONSIGNIFICANCE (DNS)
DESCRIPTION OF PROPOSAL:
IMPROVEMENTS TO 40/42 AV S FROM S 160 ST TO EAST
MARGINAL WY.
PROPONENT: CITY OF TUKWILA
LOCATION OF PROPOSAL, INCLUDING STREET ADDRESS, IF ANY:
ADDRESS:
PARCEL NO:
SEC /TWN /RNG: ALONG 40/42 AV S FROM S 160 ST TO E MARGINAL WY
LEAD AGENCY: CITY OF TUKWILA FILE NO: L93 -0031
The City has determined that the proposal does not have a probable
significant adverse impact on the environment. An
environmental impact statement (EIS) is not required under RCW 43.21c.030(2)(c).
This decision was made after review of a completed environmental
checklist and other information on file with the lead agency. This
information is available to the public on request.
Thhis determination is final and signed this _Z-41_ day of
i k Beeler, Responsible Official
City of Tukwila, (206) 431 -3680
6300 Southcenter Boulevard
Tukwila, WA 98188
You may appeal this determination to the City Clerk at City Hall, 6200
Southcenter Boulevard, Tukwila, WA 98188 no later than 10 days from the
above signature date by written appeal stating the basis of the appeal for
specific factual objections. You may be required to bear some of the
expenses for an appeal.
Copies of the procedures for SEPA appeals are available with the City
Clerk and Department of Community Development.
City of Tukwila
John W. Rants, Mayor
Department of Public Works
M E M O R A N D U M
TO: Denni Shefrin 'f
FROM: Ross BelleriVl
DATE: November 1, 1993
Ross A. Eamst, P. E., Director
RECENED
NOV 11993
GUIVilVtuNI I Y
DEVELOPMEN1
SUBJECT: 90- RW -15, 42nd Ave R/W Acquisition, L93 -0031
In response to your memo of 6/1/93, please consider the following:
1. The majority of residents wanted: sidewalks, traffic law
enforcement and design elements that will reduce vehicle speeds,
crosswalks where needed, improved drainage, better lighting and an
overall attractive appearance that will be an asset to the
community.
The project will install sidewalks on both sides of the roadway.
The all -way stop at 42/144 will remain to control volumes /speed on
the roadway. 42 will remain a two lane roadway, and crosswalks
will be installed where appropriate. The project will construct a
street drainage system which meets current standards.
Illumination on the street will be improved to a more uniform 0.6
foot candles.
2. Trees and shrubs small enough to be relocated will be excavated
and the root ball bagged so that property owners may relocate
them. There is no tree or landscape plan.
3. The detention ponds will be permanent. The location and design
will be to current standards. The locations will be chosen to
provide the most benefit (exceeding requirements if possible) and
least adverse impact if any.
6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: (206) 433 -0179 • Fax (206) 431-3665
Yf
w.s1.1.r.. nuawe lo3 uvc9 [
City of Tukwila
John W. Rants, Mayor
Department of Community Development Rick Beeler, Director
M E M O R A N D U M
TO: Brian Shelton
FROM: Denni Shefrin
DATE: June 1, 1993
SUBJECT: 42nd Avenue So. Improvements - 90 -RW15
L93 -0031.
Based upon my initial review of the SEPA Checklist, I have the
following comments:
1. How has the proposed design prepared by Public Works responded
to issues and questions raised in the Community Involvement
Program report (i.e., lighting, bikepaths, rockeries,
landscaping (maintain residential character /aesthetics)?
2. All trees which would be removed as a result of this project
should be replaced to the greatest extent possible. A tree
replacement plan should be provided which identifies the tree,
type and approximate size to be removed and the location of
the replacement tree including the tree size and type.
3. Would the propose detention ponds be permanent? What are
impacts if any?
6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • (206) 431-3670 • Fax (206) 431-3665
Control No.
Epic File No.
L93- 0031
Fee $250.00 Receipt No.
ENVIRONMENTAL CHECKLIST
A. BACKGROUND ,
1. Name of proposed project, if applicable:
Improvements to 42nd Avenue South 90 -RW15
2. Name of applicant: City of Tukwila
3. Address and phone number of applicant and contact person:
6300 Southcenter Blvd., Suite 101, Tukwila, WA 98188; 433 -0179;
Ross Heller
4. Date checklist prepared: 1/15/93
5. Agency requesting checklist: City of Tukwila
6. Proposed timing or schedule (including phasing, if applicable):
Construction is planned in three phases beginning in 1993 and
concluding in 1998..
7. Do you have any plans for future additions, expansion, or
further activity related to or connected with this.proposal? If
yes, explain.
None known.
8. List any environmental information you know about that has been
prepared, or will be prepared, directly related to this
proposal.
A SEPA checklist was prepared for the City CIP, this project was
mentioned in that document. The attached design memorandum
contains additional information including soils, wetlands, and
surface water data.
9. Do you know whether applications are pending for governmental
approvals of other proposals directly affecting the property
covered by your proposal? If yes, explain.
No applications are known to be pending.
-1-
RECEIVED
APR 2 71993
COMMUNITY
DEVELOPMENT
10. List any government approvals
your proposal.
Authorization by Tukwila City
City Mayor.
or permits that will be needed for
Council and approval of Tukwila
11. Give brief, complete description of your proposal, including the
proposed uses and the size of the project and site. There are
several questions later in this checklist that ask you to
describe certain aspects of your proposal. You do not need to
repeat those answers on this page. Section E requires a
complete description of the objectives and alternates of your
proposal and should not be summarized here.
The street improvement along 40/42nd Avenue South will include
widening the existing asphalt concrete pavement from 28 to 38
feet for parking. The roadway will remain a 2 lane street. The
roadway will not be widened where conditions warrant, such as
steep driveways and stream crossings. The improvements will
include curb, gutter & sidewalk; associated storm drainage
systems and street lighting. Overhead utilities will be placed
underground in accordance with TMC Chapter 13.08. The overall
length of the project is approximately 2 miles.
12. Location of the proposal. Give sufficient information for a
person to understand the precise location of your proposed
project, including a street address, if any, and section,
township, and range, if known. If a proposal would occur over a
range of area, provide the range or boundaries of the site(s).
Provide a legal description, site plan, vicinity map, and
topographic map, if reasonably available. while you should
submit any plans required by the agency, you are not required to
duplicate maps or detailed plans submitted with any permit
applications related to this checklist.
The project is located in the City of Tukwila, along 40/42nd
Avenue South, from South 160th Street to East Marginal Way.
The roadway is in section 22 and 15, Township 23 North, Range 4
East, W.M., City of Tukwila, King County Washington.
13. Does the proposal lie within an area designated on the City's
Comprehensive Land Use Policy Plan Map as . environmentally
sensitive?
Yes, see B. Environmental Elements, Number 8h.
-2-
TO BE COMPLETED BY APPLICANT
B. ENVIRONMENTAL ELEMENTS
Evaluation for
Agency Use Only
1. Earth
a. General description of the site (circle one): Flat, rolling,
hilly, steep slopes, mountainous, other
The terrain varies from flat to hilly with some steep slopes.
b. What is the steepest slope on the site (approximate percent
slope)?
Some areas exceed 100 %, the roadway itself will be limited to
15 %.
c. What general types of soils are found on the site (for example,
clay, sand, gravel, peat; muck)? If you know the classification
of agricultural soils, specify them and note any prime farmland.
The soils are detailed in the Subsurface Exploration and
Geotechnical Engineering Report prepared by RZA -AGRA. This
report is included in the attached design memorandum. •
d., Are there surface indications or history of unstable soils in
the immediate vicinity? If so, describe.
Some areas of erosion near /in the creek beds, and tilting of
existing retaining walls.
. e. Describe the purpose, type, and approximate quantities of any
filling or grading proposed. Indicate source of fill.
Cuts and fills will be made to accommodate the widened roadway.
Unsupported slopes will be limited to 2:1 maximum. In areas
where the slope cannot be maintained, retaining walls will be
used. Approximately 17,000 cubic yards of material is planed
for removal. A like amount gravel borrow will be imported.
f. Could erosion occur as a result of clearing, construction,or
use? If so, generally describe.
Some erosion could result from the site preparation, including
clearing and grubbing. Temporary erosion control techniques as
required will limit this to a minimal impact.
g. About what percent of the site will be covered with impervious
surfaces after project construction (for example, asphalt or
buildings)?
Approximately 82% of the site will be asphalt or concrete.
-3-
Evaluation for
Agency Use Only
h. Proposed measures to reduce or control erosion, or other impacts
to the earth, if any:
Temporary erosion control will be employed during construction
as required. Following construction, the site will be either
impervious or vegetated.
Air
a. What types of emissions to the air would result from the
proposal (i.e., dust, automobile odors, industrial wood smoke)
during construction and when the project is completed? If any,
generally describe and give approximate quantities if known.
There will be dust and exhaust emissions during construction.
Exhaust emissions along this street are not expected to increase
as the result of this project.
b. Are there any off -site sources of emissions or odor that may
affect your proposal? If so, generally describe.
No
c. Proposed measures to reduce or control emissions or other
impacts to air, if any:
Water trucks will be used as standard dust suppression during
construction.
Water
a. Surface:
1) Is there any surface water body on or in the immediate
vicinity of the site (including year -round and seasonal streams,
saltwater, lakes, ponds, wetlands)? If yes, describe type and
provide names. If appropriate, state what stream or river it
flows into.
Gilliam, and Southgate Creeks cross the proposed project.,
-4-
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•
Evaluation for
Agency Use Only
Will the project require any work over, in, or adjacent to
(within 200 feet) the described waters? If yes, please describe
and attach available plans.
Yes, work will be over and adjacent to the streams. Plans
attached.
Estimate the amount of fill and dredge material that would be
placed in or removed from surface water or wetlands and indicate
the area of the site that would be affected. Indicate the
source of fill material.
The streams will be piped under the roadway (existing 32 foot
long culverts will be extended to 42.feet to accommodate the
widening).
Will the proposal require surface water withdrawals or
diversions? Give general description, purpose, and approximate
quantities, if known.
The project includes drainage improvements which include
diverting and detaining peak flows to reduce downstream erosion.
Does the proposal lie within a 100 -year floodplain? If so, note
location on the site plan.
No.
Does the proposal involve any discharges of waste materials to
surface waters? If so, describe the type of waste and
anticipated volume of discharge.
No.
b. Ground:
Evaluation for
Agency Use Only
Will ground water be withdrawn, or will water be discharged to
ground water? Give general description, purpose, and
approximate quantities, if known.
No.
Describe waste materials that will be discharged into the ground
from septic tanks or other sources, if any (for example:
Domestic sewage; industrial, containing the following
chemicals...; agricultural; etc.) Describe the general size of
the system, the number of such systems, the number of houses to
be served (if applicable), or the number of animals or humans
the system(s) are expected to serve.
None.
c. Water Runoff (including storm water):
Describe the source of runoff (including storm water) and method
of collection and disposal, if any (include quantities, if
known). Where will this water flow? Will this water flow into
other waters? If so, describe.
The source of the runoff will be from the roadway and properties
along the route. Pipes, ditches, swales and natural water
courses will all be utilized as required design components to
convey storm water.
Evaluation for
Agency Use Only
Could waste materials enter ground or surface waters? If so,
generally describe.
Runoff from the existing roadway is likely contain automobile
oils and fuel - this project will not increase the level of
waste materials entering ground or surface waters.
d. Proposed measures to reduce or control surface, ground, and
runoff water impacts, if any:
A storm -water drainage system using biofiltration and detention
ponds and vaults is proposed.
4. Plants
a. Check or circle types of vegetation found on the site:
x deciduous tree: alder, maple, aspen, other
x evergreen tree: fir, cedar, pine, other
x shrubs
x grass
pasture •
crop or grain
x wet soil plants: cattail, buttercup, bulrush, skunk cabbage,
other (some)
x water plants: water lily, eel grass, milfoil, other
other types of vegetation
b. What kind and amount of vegetation will be removed or altered?
In areas where the roadway is widened beyond the existing
graveled shoulder; trees, brush and grass will be removed to
accommodate the street section. Vegetation which can be
relocated will be salvaged for the individual property owners.
c. List threatened or endangered species known to be on or near the
site.
None known.
Evaluation for
Agency Use Only
d. Proposed landscaping, use of native plants, or other measures to
preserve or enhance vegetation on the site, if any:
Property restoration can include seeding and planting of trees
and.shrubs.
Animals
a. Circle any birds or animals which have been observed on or near
the site or are known to be on or near the site:
birds:, hawk, songbirds, migratory water fowl.
mammals: raccoons, squirrels, small rodents
fish:
b. List any threatened or endangered species known to be on or near
the site.
None known.
c. Is the site part of a migration route? If so, explain.
No.
d. Proposed measures to preserve or enhance wildlife, if any: .
Detention ponds which will improve the flow characteristics
(fish habitat enhancement) of Gilliam and South Gate creeks are
proposed.
,•,.,wn.a,.ra�tiwatW]8^cgs5:'7M' Pty. �? i.. S':+". ?:E':r.i;Sn_:c`:t�,n�,'.,'i�%'t c: 17:a<`H t'.:'.
Evaluation for
Agency Use Only
6. Energy and Natural Resources
a. What kinds of energy (electric, natural gas, oil, wood stove,
solar) will be used to meet the completed project's energy
needs? Describe whether it will be used for heating,
manufacturing, etc.
Electric street lighting will be used.
b. Would your project affect the potential use of solar energy by
adjacent properties? If so, generally describe.
No.
c. What kinds of energy conservation features are included in the
plans of this proposal? List other proposed measures to reduce
or control energy impacts, if any:
The project will replace mercury with efficient high pressure
sodium luminaires.
7. Environmental Health
a. Are there any environmental health hazards, including exposure
to toxic chemicals, risk of fire and explosion, spill, or
hazardous waste, that could occur as a result of this proposal?
If so, describe.
No.
1) Describe special emergency services that might be required.
None.
2) Proposed measures to reduce or control environmental health
hazards, if any:
Not applicable..
Evaluation for
Agency Use Only
b. Noise
1) What types of noise exist in the area which may affect your
project. (for example: traffic, equipment, operation, other)?
Not applicable.
2). What types and levels of noise would be created by or
associated with the project on a short -term or long -term basis
(for example: traffic, construction, operation, other)? Indicate
what hours noise would come_ from the site.
Noise generated by the construction equipment will occur on a
short term basis.
3) Proposed measures to reduce or control noise impacts, if
any:
Operation restricted to the hours between 7 a.m. and 7 p.m..
Land and Shoreline Use
a. What is the current use of the site and adjacent properties?
The site is currently a two -lane paved roadway in a residential
neighborhood.
b. Has the site been used for agriculture? If so, describe.
No.
c. Describe any structures on the site.
Some mobile homes encroach on the right -of -way, and may need to •
be relocated.
Evaluation for
Agency Use Only
d. Will any structures be demolished? If so, what?
No.
e. What is the current zoning classification of the site?
The adjacent properties vary from R -1 to RMH.
f. What is the current comprehensive plan designation of the site?
The plan designation for the adjacent properties varies from low
to high density residential.
g. If applicable, what is the current shoreline master program
designation of the site?
Not applicable.
h. Has any part of the 'site been classified as an "environmentally
sensitive" area? If so, specify.
Yes, Gilliam and Southgate creeks.
i. Approximately how many people would reside 'or work in the
completed project?
None.
j. Approximately how many people would the completed project
displace?
None (see Item 8c above).
k. Proposed measures to avoid or reduce displacement impacts, if
any:
None.
1. Proposed measures to ensure the proposal is compatible with
existing and projected land uses and plans, if any:
The roadway will be constructed as a residential street.
Evaluation for
Agency Use Only
Housing
a. Approximately how many units would be provided, if any?
Indicate whether high, middle, or low- income housing?
None
b. Approximately how many units, if any, would be eliminated?
Indicate whether high, middle, or low- income housing.
None
c. Proposed measures to reduce or control housing impacts, if any:
Not applicable
LO. Aesthetics
a. What is the tallest height of any proposed structure(s), not
including antennas; what is the principal exterior building
material(s) proposed?
No buildings are planned. Retaining walls will be limited to
minimum required. Overhead utilities will be relocated
underground.
b. What views in-the immediate vicinity would be altered or
obstructed?
None.
c. Proposed measures to reduce or control aesthetic impacts, if
any:
None.
Evaluation for
Agency Use Only
11. Light and Glare
a. What type of light or glare will the proposal produce? What
time of day would it mainly occur?
Public meetings have indicated a need for increased
illumination. The existing lighting will be removed as
utilities are placed underground. New poles will be installed
to provide an average horizontal foot candle of 0.6 with a
uniformity ratio of 4:1 or better.
b. Could light or glare from the finished project be a safety
hazard or interfere with views?
The proposed system is expected to improve public safety.
c. What existing'off -site sources of light or glare may affect your
proposal?
None.
d. Proposed measures to reduce or control light and glare impacts,
if any:
None.
12. Recreation
a. What designed and informal recreational opportunities are in the
immediate vicinity?
South Gate park.
b. Would the proposed project displace any existing recreational
uses? If so, describe.
No.
c. Proposed measures to reduce or control impacts on recreation,
including recreation opportunities to be provided by the project
or applicant, if any:
None.
-13-
Evaluation for
Agency Use Only
3. Historic and Cultural Preservation
a. Are there any places or objects listed on, or proposed for,
national, state, or local preservation registers known to be on
or next to the site? If so, generally describe.
None known.
b. Generally describe any landmarks or evidence of historic,
archaeological, scientific, or cultural importance known to be
on or next to the site.
None known.
c. Proposed measures to reduce or control impacts, if any:
None.
.4. Transportation
a. Identify public streets and highways serving the site, and
describe proposed access to the existing street system. Show on
site plans, if any.
The proposal is for improvement of an existing public street.
b. Is the site currently served by public transit? If not, what is
the approximate distance to the nearest transit stop?
Yes, METRO transit stops are located along the street.
c. How many parking spaces would the completed project have? How
many would the project eliminate?
The project is providing on street parking to balance the loss
of existing parking on the gravel'shoulder and driveways.
:>
Evaluation for
Agency Use Only
d. Will the proposal require any new roads or streets, or
improvements to existing roads or streets, not including
driveways? If so, generally describe (indicate whether public or
private).
No.
e. Will the project use (or occur in the immediate vicinity of)
water, rail, or air transportation? If so, generally describe.
No.
f. How many vehicular trips per day would be generated by the
completed project? If known, indicate when peak volumes would
occur.
g.
This project is not expected to result in more vehicle traffic.
The all -way stop at S 144 St. will maintain existing north /south
. traffic capacity so peak volumes will not increase or divert.
from Pacific Highway to 40/42. Ped traffic is expected to
increase with the addition of sidewalks.
Proposed measures to reduce or control. transportation impacts,
if any:
None.
15.Public Services
a.' Would the project result in an increased need for public
services (for example: fire protection, police protection,
health care, schools, other)? If so, generally describe.
No increase is expected.
b. Proposed measures to reduce. or control direct impacts on public
services, if any.
None.
Evaluation for
Agency Use Only
6.Utilities
a. Circle utilities currently available at the site: electricity,
• natural gas, water, refuse service, telephone, sanitary sewer,
septic system, other.
All utilities are available, they are limited in some areas.
b. Describe the utilities that are proposed for the project, the
utility providing the service, and the general construction
activities on the site or in the immediate vicinity which might
be needed.
ignature.
No new utilities are proposed with the project, existing
overhead utilities will be placed underground.
The above answers are true and complete to the best of my
knowledge. I understand that the lead agency is relying on them
to make its decision.
Signature:
gate Submitted:
a-rt.-OAAr■- •
4-1zA--193
LEASE CONTINUE TO THE NEXT PAGE.
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Evaluation for Agency Use Only
E. SUPPLEMENTAL SHEET FOR ALL PROJECT AND NON PROJECT PROPOSALS
The objectives and the alternative means of reaching the
objectives for a proposal will be helpful in reviewing the
foregoing items of the Environmental Checklist. This information
provides a general overall perspective of the proposed action in
the context of the environmental information provided and the
submitted plans, documents, supportive information, studies,
etc.
I. What are the objectives of the proposal?
Improve 40 /42nd Avenue South to increase safety for pedestrian
and vehicle traffic and to provide on- street parking.
2. What are the alternative means of accomplishing these
objectives ?.
None.
3. Please compare the alternative means and indicate the preferred
course of action:
4. Does the proposal conflict with policies of the Tukwila
Comprehensive Land Use Policy Plan?
No
Proposed measures to avoid or reduce the.conflict(s) are:
None.
1
Design N•t mo ar7.••9ui
for
IMPROVEMENTS To 42ND AVENUT, SOUTH
+.■ _ T ...• .. r.A t -• +rry •r
reel: to South 130th
Street
Prepared for
City of Tukwila of .L. uk *tiila
Department of Public Works
z
tt
•
Prepared by
Perfect
1 .I Engineering, Inc.
Civil and Trunspn•iation Consultants
Aprii, 1992
1
DESIGN MEMORANDUM FOR
IMPROVEMENTS TO 42ND AVENUE SOUTH
South 160th Street to South 130th Street .
April, 1992
Prepared for:
THE CITY OF TUKWILA
Department of Public Works
6200 Southcenter Boulevard
Tukwila, Washington 98188
Prepared by:
PERTEET ENGINEERING, INC.
Civil and Transportation Consultants
2828 Colby Avenue, Suite 410
Everett, Washington 98201
(206) 252 -7233
• Project No. 91256
IFIRES: 9/30/ 9Z
TABLE OF CONTENTS
Section Pape
Executive Summary 1
Design Criteria 2
Alignment 2
Parking 3
Right -of -Way 3
Soils 4
Pavement 4
Traffic / Transit 5
Storm Drainage 9
Environmental 12
Wetlands 13
Utilities 13
Illumination 14
Project Cost Estimates 14
Table
Pape
Table 1 - 42nd Avenue South Design Criteria 2
Table 2 - 42nd Avenue South Subgrade Geotechnical Summary 4
Table 3 - Approximate Daily Traffic Volumes for Various Levels of • Service 6
Table 4 - Level of Service Summary 6
Table 5 - Accident Summary 7
Table 6 - Signal Warrant Analysis 8
Follows
Figure Pape
Figure 1 - Vicinity Map 1
Figure 2 - Typical Roadway Section 2
Figure 3 - Typical Roadway Section 2
Figure 4 - Typical Roadway Section 2
Figure 5 - Existing and Future Traffic Volumes 5
Figure 6 - PM Peak Turning Volumes - Existing and Future 8
Figure 7 - Traffic Signal Layout -S. 154th Street 9
Figure 8 - Drainage Map - Gilliam Creek Basin 9
Figure 9 - Drainage Map- Fostoria Basin 9
Appendix A
Appendix B -
Appendix C
Appendix D
- Plan and Profile.
Traffic Data
- Text from Geotechnical Engineering Report
- Summary of Community Involvement Program
EXECUTIVE SUMMARY
The proposed project is approximately 2.0 miles in length running from South 160th Street to East
Marginal Way, as shown in Figure 1 (Vicinity Map). Within these limits the roadway will consist
of three different roadway sections. From South 160th Street to South 139th Street a 38 foot and
' 32 foot section will be used. The 38 foot section will provide an 11 foot driving lane, an eight
foot parking lane, curb, gutter and sidewalk on either side of centerline. The 32 foot section will
provide an 11 foot driving lane, an 8 foot parking lane, curb, gutter and sidewalk on one side, a
13 foot driving lane, curb, gutter and sidewalk on the opposite side, based on existing access
feasibility. From S. 139th Street to East Marginal Way a 26 foot section will be provided to
accommodate access to adjacent properties with steep roadway slopes and in some areas the 32
foot section will be used to provide on -street parking when feasible. The 26 foot section will
consist of 13 foot lanes with curb, gutter, and sidewalk on each side. Utilities along this project
will be moved to underground. Illumination will be installed along the entire length of the
project.
The project is divided into three phases along 42nd and 40th Avenue South. The phases are as
follows:
PHASE LIMITS
1 South 154th to South 139th Street (includes S. 154th signal)
2 South 139th Street to East Marginal Way
3 South 160th to South 154th Street
Phase 1 improvements include roadway widening, asphalt overlay and replacement, curb, gutter,
and sidewalk each side, parldng on both or one side, storm drainage, continuous lighting, and
traffic signal at South 154th Street. A small off -site detention pond may be constructed during
this phase.
Phase 1 project costs are estimated to be $2,032,000 exclusive of right -of -way and
undergrounding of overhead utilities.
Phase 2 improvements include roadway widening, asphalt overlay and replacement, curb, gutter,
and sidewalk each side, limited parking, storm drainage, and continuous lighting. Detention Pond
4 will be constructed during this phase.
Phase 2 project costs are estimated to be $1,272,000 exclusive of right -of -way for storm water
detention facilities and undergrounding of overhead utilities.
Phase 3 improvements include roadway widening, asphalt overlay and replacement, curb, gutter,
and sidewalk each side, parking on both or one side, storm drainage, and continuous lighting.
Detention Ponds 1 & 2, will be constructed during this phase.
Phase 3 project costs are estimated to be $884,000 exclusive of right -of -way for storm water
detention facilities and undergrounding of overhead utilities.
Total project costs are estimated to be $4,188,000 exclusive of right -of -way and undergrounding
of overhead utilities.
Right -of -way needs for roadway construction are limited to Phase 1 and impact 49 parcels. The
area of acquisition is 0.55 acres. Right -of -way is also required for detention pond construction in
all three phases. These areas have not been determined at this time, due to limited topographic
survey data.
42nd Avenue S.E. City of Tukwila
Design Report Page 1
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Civil and .Transportation Consultants
• 42nd AVENUE SOUTH
Vicinity Map
Figure 1
DESIGN CRITERIA.
Design criteria were established for the 42nd Avenue South improvements which are consistent
with the current road classification, existing and projected traffic, pedestrian needs, land use, and
desired safety improvements Table 1 lists the design criteria for the project. Items not noted will
be in accordance with the City of Tukwila policies and standard roadway design practices.
Eleven -foot minimum travel lanes and eight -foot parking lanes are proposed for the vehicular
surfacing with five -foot sidewalks adjacent to the back of curb on both sides of the roadway. The
proposed roadway sections are shown in Figures 2, 3, & 4.
TABLE 1
42ND AVENUE SOUTH DESIGN CRITERIA
Posted Speed
Design Speed
Stopping Sight Distance
Entering Sight Distance
Superelevation
Grade
Right -of -Way
Through -Lane Width
Left -Turn Lane Width
Parking Lane Width
Sidewalk Width
Intersecting Street Width
Intersecting Street Curb Radius
Clear Zone
25 MPH
35 MPH
225 feet minimum, 250 desirable
420 feet minimum
6% max. cross slope
15% maximum
60 feet minimum
11 feet minimum
12 feet
8 feet
5 feet
24 feet minimum
35 feet
18 inches back of curb
ALIGNMENT
The construction centerline of 42nd Avenue South will be the right -of -way centerline and lies on a
tangent (along section lines) throughout the project length except where the centerline diverges just
north of South 144th Street. The center two eleven foot lanes will be constructed symmetrically
about the roadway centerline, while either the parking lane or the additional two feet of pavement
in the thirteen foot through lanes will be constructed adjacent to the outer edge of the two center
eleven foot lanes.
Minor adjustments will be made to the vertical alignment to improve sight distance and to more
closely match existing edge conditions at the property lines. The largest adjustment is anticipated
near the reverse curves just north of South 139th Street, where steep driveways and adjacent
properties will experience the greatest impacts from the widening of 42nd Avenue South. At the
vicinity of South 160th Street a cut of approximately 1 foot is needed to improve stopping sight
distance to the desirable minimum.
Generally, Keystone Walls with isolated rockeries will be used to contain the roadway fill within
the right -of -way and will range to a maximum height of ten feet. Where roadway fill or cut
slopes endanger existing structures or facilities on adjacent properties, reinforced concrete walls
will be used to contain the slopes within the right -of -way. These walls range up to 14 feet in
height.
42nd Avenue S.E. City of Tukwila
Design Report Page 2
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Intersecting streets will be widened at the approach and tapered to existing pavement in
approximately 100 feet. Curb, gutter and sidewalks will be constructed around the radii and will
be located so that future widening of side streets can be accomplished with minimum cost and
reconstruction.
Sidewalks will be cement concrete, five feet in width on both sides of the street for the entire
length of the project.
PARKING
On street parallel parking on both sides of the roadway was looked at for the entire length of the
project. A review of driveway grades and the impact widening for parking and sidewalk would
have on them was conducted. It was determined that on street parallel parking would have to be
limited to one side only or in a few cases, no parking. The areas that have parking limited to one
side or no parking only are as follows:
NO
VICINITY PARKING
South 152nd to South 151st Street West Side
South 150th to South 148th Street East Side
South 139th Street to East Marginal Way Both Sides
From South 139th Street to East Marginal Way a review of on -street parking needs and driveway
profiles was conducted from aerial photographs and field surveys. It was determined that
widening for parking could be provided in three areas from the bottom of the S -curve to East
Marginal Way. The widened areas are as follows:
1. East Side - Vicinity Station 141 +00 to 142 +00
2. West Side - Vicinity Station 143 +00 to 145 +00
3. East Side - Vicinity Station 147 +00 to 149 +00
RIGHT-OF-WAY
The existing right -of -way varies in width from 50 feet to in excess of 60 feet. Available right -of-
way is considerably wider in the location of SR 518.
Additional right -of -way will need to be acquired to provide a minimum width of 60 feet to
accommodate the selected roadway sections. Potential right -of -way acquisition may also be
desirable for location of proposed detention facilities to be constructed in conjunction with the
roadway improvements.
The need for additional right -of -way to accommodate roadway widening is within the proposed
phase 1 limits, South 154th Street to South 139th Street. A total of 49 parcels will be impacted
and the area of right -of -way to be acquired is approximately 0.55 acres.
Temporary permits will be required for driveway reconstruction beyond the roadway right -of -way
to provide adequate match -in to the existing residences or commercial sites.
Right -of -way need for detention ponds is identified in the storm drainage section under the title,
"Storm Drainage /Right -Of -Way.
42nd Avenue S.E. City of Tukwila
Design Report • Page 3
SOT S
Rittenhouse -Zeman and Associates, Inc. has provided geotechnical recommendations for the
design and construction of the improvements. This report "Subsurface Exploration and
Geotechnical Engineering Report, 42nd Avenue South Improvement Project" is available as a
separate document. The text of this report is provided in Appendix C.
The soils report identifies four different soil and pavement conditions along 42nd and 40th Avenue
South. The conditions identified are poor, fair, good (no- overlay), and good (overlay).
Poor soils exist along approximately 800 linear feet of the project in two sections, the section from
SR 518 to. South 154th Street and South 142nd to South 141st Street. It is recommended to
overexcavate 2 feet and place geotextile reinforcement fabric above the subgrade, this is to avoid
overexcavating all unsuitable to depths as great as 16 feet. It should be noted that additional
excavation greater than 2 feet may be needed if organic -rich materials are exposed upon the initial
stripping.
Fair soils exist along approximately 1100 linear feet of the project in two sections, the section
from South 160th to South 158th Street and South 148th to South 146th Street. It is recommended
to overexcavate the upper 2 feet of the existing subgrade and replace it with compacted import
sand and gravel.
Good soils and distressed pavement exist along 2700 linear feet of the project. It is recommended
to overexcavate 2 feet below the bottom of pavement in these sections.
Approximately 5700 linear feet of the project is suitable for a pavement overlay. In these areas
the soil is good and the existing pavement does not appear to be distressed.
PAVEMENT
The proposed pavement depths are based on recommendations by Rittenhouse Zeman &
Associates as determined by their geotechnical investigation report which is available under
separate cover. A summary of their findings is shown in Table 2.
TABLE 2
42ND AVENUE SOUTH SUBGRADE GEOTECHNICAL SUMMARY
From Station To Station Subgrade Condition
50 +50 56 +00 Fair
56 +00 68 +00 Good (overlay)
68 +00 72 +00 Poor
72 +00 83 +00 Good (no overlay
83 +00 92 +00 Good (overlay)
92 +00 97 +00 Fair
97 +00 108 +00 Good (no overlay
108 +00 112 +00 Poor
112 +00 136 +00 Good (overlay)
136 +00 141+00 Good (no overlay
141 +00 153 +00 Good (overlay)
42nd Avenue S.E.
Design Report
City of Tukwila
Page 4
Recommendations for each of the subgrade conditions encountered are:
Poor Subgrade
• Over excavate two feet below finished subgrade
• Proof roll the exposed subgrade
• Place geotextile reinforcement over exposed subgrade
• Construct 2 feet of import sand and gravel sub -base
• 6" Crushed Aggregate Base Course
• 4" Asphalt Treated Base
• 4" Asphalt Pavement
Fair Subgrade
• Overexcavate 2 feet below finished subgrade
• Reconstruct 2 feet of import sand and gravel sub -base
compacted to 95 % min. of modified proctor
• 6" Crushed Aggregate Base Course
• 4" Asphalt Treated Base
• 4" .Asphalt Pavement
Good Subgrade (With or without overlay)
• Compact 2 feet of subgrade to 95 % min. of modified proctor
• 4" Asphalt Treated Base
• 4" Asphalt Pavement
The existing pavement will be overlaid with a minimum of 0.15 feet (2 inches) of Class B asphalt
and the roadway widened using 0.33 feet (4 inches) of asphalt over .33 feet (4 inches) of asphalt
treated base.
TRAFFIC / TRANSIT
Traffic Volumes
Existing traffic along 42nd Avenue South between South 160th Street and South 130th Street is
approximately 3,000 to 6,300 vehicles per day.
A twenty year forecast is the normal maximum travel forecast period for arterial streets.
Projected volumes for the year 2010 were computed using a straight -line interpolation; an annual
growth rate of 2.5 percent was added to existing volumes. This 2.5 percent value was obtained by
interpreting a traffic model, entitled Tukwila Trafc Model, previously prepared for the City of
Tukwila. 42nd Avenue S. will reach an approximate volume of 10,000 vehicles per day by the
year 2010, or twenty years in the future. Figure 5 illustrates the existing and projected traffic
volumes along the route.
As shown on Table 3, a two lane arterial street has an approximate capacity of 11,000 vehicles per
day given "average conditions". Since the capacity of an urban street is governed by the capacity
of individual intersections along the route, the capacity values listed can vary widely depending on
turning volumes, signal coordination, etc. Based on the 20 year projected rate of growth a two
lane configuration is adequate for the future traffic volumes along this route.
42nd Avenue S.E. City of Tukwila
Design Report Page 5
3540
S. 1257H ST
S. 125TH ST.
(5600)
4600
(73001
5. 12871.4 57.
S. 130TH ST. v
W
5. 133RD ST.
S. 134TH ST.
3080
(4900)
5. 139TH 57.
5. 140714 ST
5960
(9100)
2830
(4463)
5. 14157 57.
7160
011300)
6160
C9700)
5. 144TH 57.
6070
5.14Z1.'0 57. (9600)
5.1467H ST.
S. 148TH ST.
z
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rt
5. 150TH 57.
S. 152ND 57.
S. 154TH ST.
4870
(7700)
6260
(9900)1 8550
/1135001'
5. 160T14 57.
S. 158714 ST.
S. 160714 ST.
ti
i
5. 154TH ST.
5500
(8806)
6340
(10000)
LEGEND
000
(000)
1991 A.D.T
2010 A.D.T
Perteet Engineering, Inc.
42nd AVENUE SOUTH
Existing & Future
Civil and Transportation Consultants . • Traffic Volumes
Figure 5
•
•
•
TABLE 3
APPROXIMATE DAILY TRAFFIC VOLUMES
FOR
VARIOUS LEVELS OF SERVICE*
Number of Lanes LOS C LOS D LOS E
Two 8,000 10,000 11,000
Three 12,000 14,000 16,000
Four 20,000 22,000 24,000
Five 24,000 26,000. 30,000
Six 27,000 30,000 33,000
Seven 30,000 35,000 38,000
* Based on the "Crossroads Study and Subarea Plan ",
City of Bellevue Planning Department, June, 1979.
Level of Service
Levels of Service (LOS) are qualitative descriptions of traffic operating conditions. These levels
of service are designated with letters ranging from LOS A, which is indicative of good operating
conditions with little or no delay, to LOS F, which is indicative of stop -and -go conditions with
frequent and lengthy delays. Levels of service for the analysis of the major intersections were
calculated using the methodology of the 1985 Highway Capacity Manual with the NCAP computer
program developed by a division of Metro Transportation Group, Inc. Table 4 shows the existing
and year 2010 levels of service for the major intersections.
TABLE 4
LEVEL OF SERVICE SUMMARY
1991
Location Existing LOS 2010 LOS
South 130th Street A A - B
South 144th Street A Average D
South 154th Street A - B Average E
Using 2010 volumes and assuming signals are installed at South 154th Street, the LOS at this
intersection becomes B.
42nd Avenue S.E.
Design Report.
City of Tukwila
Page 6
Accidents
During the period from January 1, 1980 to July 9, 1991 seventeen accidents occurred on 42nd
Avenue South between South 160th Street and South 130th Street. One occurred in 1987, none in
1988, four in 1989, eight in 1990, and four in 1991. There were thirteen injuries and no
fatalities. The predominant type of accidents are vehicles striking parked vehicles (7) and right -
angle accidents (6). This indicates inadequate shoulder width and needed intersection
improvements. The accident rate for this section of roadway is 0.99 accidents per 1 million
vehicles miles driven and the county -wide accident rate for this type of roadway is 5.2 accidents
per 1 million vehicle miles driven. This roadway is well below the county average. Table 5
summarizes the accidents.
42nd Avenue S.E.
Design Report
City of Tukwila
Page 7
TABLE 5
ACCIDENT SUMMARY
•
Year Location
Parked
Vehicle
Right
Anele
Pedestrian
Bicycle
Approach
Turn Sideswipe
Other
Had Been
Drinking
1987 South 131st St.
1
1988 N/A
1989 South 133rd St.
South 139th St.
South 140th St.
South 148th St.
1
1
1
1
1
1990 South 130th St.
South 134th St.
South 144th St.
South 152nd St.
South 154th St.
South 160th St.
1
1
1
1
1 1
,
1
2
•
•
•
1
1
1
1991 South 140th St.
South 142nd St.
South 144th St.
South 154th St.
1
1
1
1
1
1
Totals
7
6
1
1
1
1
6
Day
Night
Dawn
9
7
1
Dry
Rain
Ice
8
8
1
AM
PM
Southbound
4
13
10
42nd Avenue S.E.
Design Report
City of Tukwila
Page 7
Signal Warrant Analysis
Traffic signal warrants are used to determine whether or not a signal should be considered at an
existing unsignalized intersection.
These warrants have been established to provide a set of criteria that can be used to define the
relative need for, and appropriateness of, traffic signal controls and are usually expressed in the
form of numerical requirements such as traffic volumes, accidents, pedestrians, etc. There are 11
signal warrants for traffic signals and are described in the Manual on Uniform Traffic Control
Devices (MUTCD). Only the warrants related to volume have been considered for the major
intersections on 42nd Avenue S.
A review of all traffic volumes of the intersections between S. 160th Street and S. 130th Street
was conducted to determine if signals are warranted at any location. The results of these analyses
are shown on Table 6, while the volumes of the major intersections and their movements are
shown on Figure 6.
TABLE 6
SIGNAL WARRANT ANALYSIS
Location
South 130th Street to South 142nd Street
South 144th Street
South 146th Street to South 152nd Street
South 154th Street
Warrants
No warrants
3 hours warrant #1
Minimal warrant #11
No warrants
6 hours warrant #1
2 hours warrant #2
Met warrant #9
Met warrant #11
South 158th Street to South 160th Street No warrants
Comments
Minimum volumes
Peak hour volumes
Minimum volumes
Interruption)
Four hour volumes
Peak hour volumes
Pedestrians and Cyclists
The majority of the project will include an eight foot asphalt parldng strip on one or both sides of
the two 11 foot center through lanes, while the balance of the project will have 13 foot wide
through lanes. In all cases, there will be a minimum of 13 feet from centerline to each face of
curb. The entire project will have sidewalks on both sides of the roadway.
Pedestrians will have access to five foot sidewalks on the east and west sides of 42nd / 40th
Avenue South with wheelchair ramps provided at all intersections. Crosswalks will be clearly
marked where appropriate.
The eight foot asphalt parking strip or the edge of the 13 foot through lane will provide adequate
provisions for bicycles to negotiate the route.
42nd Avenue S.E.
Design Report
City of Tukwila
Page 8
5. 125714 ST
5. 128TH ST.
5. 130714 5T.
12811.1
S. 133R0 ST.
S. 134TH ST.
S. 139TH ST.
5. 140TH ST.
5. 141S7 5T.
S. 144TH 5T.
S. 142N0 5T,
S. 1467H ST,
5. 148714 5T.
(41) 25
(60) (420) (17)
38 265 11
J�L
(100) 63 -+•
(19) 12
S. 150TH 5T.
S. 152N0 ST.
S. 154TH 57.
t r
33 84 25
(52) (133) (40)
7 (11)
72 (1141
59 (94)
(117) (327) (54)
74 207 34
f i
(103) 65 22 (35)
(281) 178-8... • - 163 (258)
(103) 65 J 47 (7 4)
%►r
52 72 50
(82) (114)(79)
(57) (395) (114)
36 250 72
J }L
(19) 12 J 78 (123)
(294) 186
(63) 40
S. 160TH ST.
LEGEND
. xxx 1991
txxx) • 2011
5. 158TH 5T
S. 16Q714 ST
.0
5. 1641'14 ST,
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212 (335
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31 101 68
(491 (160) 007)
' Perteet Engineering.Inc.
Civil and Transportation Consultants
42nd AVENUE SOUTH
PA Peak Turning Volumes
Existing and Future
Figure 6
Channelization and Signalization
The configuration of the intersection channelization for 40th Avenue South and South 130th Street
will remain the same. It is a four leg intersection and presently provides left turn channelization
on all four legs.
The intersection of S 144th Street & 42nd Avenue South is a four way stop without left turn
channelization. The configuration of this intersection will remain unchanged.
Channelization of the four leg intersection of 42nd Avenue South and South 154th Street presently
has left turn lanes for eastbound and westbound traffic to turn onto 42nd Avenue South The
channelization will be modified to include left turns for northbound and southbound traffic on
42nd Avenue South to turn onto South 154th Street to compliment the proposed signalization of
the intersection based on the warrant analysis (Figure 7).
Transit
Metro transit currently provides bus service along 42nd Avenue South via Route 124 which serves
the Seattle and Tukwila areas.
The street design will include the following to accommodate Metro Transit:
1. Eight foot sidewalks ten feet in length at bus stops where right -of -way permits.
2. Full roadway illumination.
3. Sufficient curb radii for busses to "stay in lane ".
4. On- street bus stops for both northbound and southbound busses will be provided at the
following locations:
Northbound
• 165 feet south of South 130th Street
• 40 feet south of South 128th Street
.• 100 feet south of South 131st Street
Southbound
• at South 128th Street
• 170 feet south of South 130th Street
• 55 feet south of South 130th Street
STORM DRAINAGE
Existing Conditions
The 42nd Avenue project lies within two separate drainage basins. The Gilliam Creek Basin lies
south of South 144th Street and the Fostoria Basin lies within the northern portion of the project.
The southern portion of the project has two major water courses crossing 42nd Avenue and the
combined catchment area is approximately 807.4 acres, which converges at an existing depression
on the north side of South 154th Street just east of the subject project (see Figure 8). The
depression is approximately 30 feet in depth with an active storage volume of approximately 28
42nd Avenue S.E. City of Tukwila
Design Report Page 9
r
42nd AVENUE S.
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Ported Enginooring,Inc.
Civil and Transportation Consultants
42nd AVENUE SOUTH
DRAINAGE AMP
FOSTORIA BASIN
Figure 9
acre feet. Outfall from this depression is via an existing 30 -inch diameter pipe which is in poor
condition and has limited maintenance access as it extends to the east approximately 0.3 miles.
The northern portion of the project likewise has two major water courses crossing 42nd Avenue.
These drainageways have been identified by a previous report for Fostoria Basin in May of 1986
as the north and south branches of the natural channel between 40th and 42nd Avenue South (see
Figure 9).
The combined catchment for both branches of the northerly drainage is approximately 269.3 acres.
Of the combined area, 47.6 acres are collected and discharged from 42nd Avenue South through
existing drainage facilities.
Adjacent property along the entire project has experienced drainage problems. These manifest
themselves as localized flooding, severe downcutting of the stream channels and sedimentation
downstream. Several of the existing culverts have riser type controls at their inlets, designed to
provide sediment traps along the drainage corridors. These measures provide only minimal
improvements and require frequent maintenance to operate properly.
The overall drainage basins experience flooding problems due to undersized drainage features for
the extent of current development.
Proposed Improvements
The 42nd Avenue South project bisects the Fostoria and Gilliam Creek drainage basins, separating
their extreme headwaters from their outfalls to the Duwamish River. Approximately 236.4 acres
of the Gilliam Creek basin and 47.6 acres of the Fostoria Creek basin can be intercepted by the
project and directed to intermediate detention facilities. It is beyond the scope of this project to
solve the major drainage problems within these basins, however, in -the process of designing the
42nd Avenue roadway improvements it would be prudent to combine the required detention and
biofiltration for the additional roadway with facilities which would reduce the existing problems
within the basins to the extent budget allows.
Gilliam Creek Basin
Three sites have been identified as potential detention facilities. They are designated as Detention
Pond #1, Regional Pond #2, and Detention Pond #3 on Figure 8. Sub - basins and their surface
flows which can be collected by 42nd Avenue have been identified as sub - basins A through F.
Preliminary calculations indicate that Detention Ponds #1 and #3 will provide approximately
150,000 and 45,000 cubic feet of detention storage respectively. The Regional Pond #2 can
provide approximately 1,200,000 cubic feet of active detention storage.
The Water Works Program, "Santa Barbara Urban Hydrograph Method of Analysis" was used to
estimate flows from the contributing areas within the upstream basins and sub - basins. It was
determined that given no detention facilities exist upstream of the site, Detention Ponds #1 and #3
are only adequate to attenuate the 2 -year storm event. Although they are unable to store larger
storms, it is still recommended they be developed to control low flows and direct them to the
biofiltration facilities.
It is recommended that sub - basins A, B & C be collected by the 42nd Avenue drainage system and
outfall into Detention Pond #1. A diversion structure would direct low flows through a
biofiltration swale prior to discharge into the detention facility while high flows would bypass the
swale and outfall directly into the detention pond. The control structure will be designed to
maximize the pond volume for the 2 -year storm prior to entering the culvert which crosses 42nd
Avenue South. It is proposed that the existing 36 inch diameter culvert be replaced with a 48 -inch
42nd Avenue S.E. City of Tukwila
Design Report Page 10
diameter culvert in accordance with the previous report and the finding of the preliminary project
calculations.
Runoff from sub - basins E & F can be collected and piped to Detention Pond #3. As with
Detention Pond #1, the control structure would be designed to maximize the pond volume for the
2 -year event and bypass greater flows to Regional Pond 1/2.
There is no apparent location for biofiltration facilities for sub - basins D, E & F within the existing
right -of -way. It is therefore proposed that the outfall from Detention Pond #3 continue south
along 42nd Avenue as the roadway drainage collection system to South 152nd Street. At South
152nd Street, the drainage system would follow the existing 20 foot right -of -way easterly to the
depression identified as Detention Pond #2. It is proposed to construct a 200 foot biofiltration
swale adjacent to the pipe within the 20 foot right -of -way in the reach with the least gradient. A
diversion structure will be constructed in -line to divert low flows to the biofiltration swale. At the
downhill end of the swale, a second structure would collect the flows after filtering and route them
back into the piping system. Heavy flows from major storm events will travel entirely as pipe
flow along the existing South 152nd Street right -of -way to Regional Pond #2.
By routing the major storm flows through the piping system from Detention Pond 113 to Regional
Pond #2, the severe downcutting experienced between 148th Avenue South and Regional Pond #2
will be greatly reduced if not entirely eliminated. In addition to this approximately half of Sub -
basin D's flow can be collected and discharged into Regional Pond #2 without impacting either
undersized culvert at 42nd Avenue South or South 154th Street. The remainder of Basin D will be
collected along 42nd Avenue South and outfall into Detention Pond #1.
The existing depression /Regional Pond #2 with its 30" diameter outfall has the capacity to
attenuate up to the 25 -year storm event. Design revisions to the outfall control (such as addition
of orifice or weir controls) can increase the detention for low flows, such as the 2 and 10 -year
event, thus relieving some of the flooding potential downstream of the facility for those storms.
Fostoria Basin
One site has been identified as a potential open pond detention facility for the northern portion of
the project. It has been designated as Detention Pond #4 on Figure 9. Its location is between two
existing water courses just south of South 133rd Street and north of existing Southgate Park
property. Access to Detention Pond #4 for .construction and maintenance would be along the
unopened right -of -way for South 134th Street.
Sub - basins G, H & J can be collected by the drainage system in the 42nd Avenue South project.
Existing contours indicate that street drainage can be piped to the unopened right -of -way for South
134th Street. From this point, the 2 -year storm runoff can be directed to a biofiltration swale
within the 134th Street right -of -way prior to outfall to Detention Pond #4. Larger storm event
runoff can be piped from 42nd Avenue to the pond directly.
Sub -basin I is currently collected within the existing water course which crosses 42nd at the north
west corner of Southgate Park. Flows in the existing channel can be intercepted as it crosses the
right -of -way for South 134th Street and directed to Detention Pond #4. None of the runoff from
sub -basin I originates on the paved surfaces of the 42nd Avenue project, therefore, it will not
require biofiltration prior to outfall into the detention facility.
Alternatives to the proposed Detention Pond #4 are being prepared under a separate study. They
include, construction of detention ponds within the stream corridor both immediately upstream and
downstream of 42nd as well as research of a previous design by King County. Potential in -creek
detention is shown on Figure 9. Computer analysis of the alternatives are not available to date.
However, results of the study and incorporation of the stream enhancements desired by the City
42nd Avenue S.E. City of Tukwila
Design Report Page 11
will be available prior to final design of the future construction of the northern portion of the
project.
Preliminary calculation indicate that Detention Pond #4 has adequate capacity to attenuate design
flows up to the 100 -year storm event. Therefore, construction of the facility will greatly reduce
the flooding potential downstream of the project.
Phase 1 Construction
The proposed limits of Phase 1 construction are from South 154th Street to South 139th Street.
Due to the elevation constraints, the southern limits of Phase 1 construction should be where
Gilliam Creek crosses 42nd Avenue just north of SR 518. Roadway construction could end with
the intersection improvements at South 154th Street and 42nd, however, the drainage system needs
to extend to its outfall in Gilliam Creek.
The natural high point which divides the Gilliam Creek and Fostoria Basins occurs at South 144th
Street. As the northern limit of Phase 1 construction is at South 139th Street, it is recommended
that drainage improvements between 144th and 139th be constructed for the roadway only. The
collection system will be designed to match the future improvements to the north, while detention
for the additional impervious surfaces on 42nd Avenue can be contained in the underground
drainage pipes along 42nd at this time. Detention is proposed as 60 inch diameter. pipes within
the roadway at the intersection of 42nd Avenue South and South 139th Street (see Figure 9).
Outfall from the detention pipes and biofiltration improvements can be constructed within the
existing ditch along the south right -of -way of 139th. When the northern portion of 42nd Avenue
is completed, sub -basin G can be rerouted to Detention Pond #4.
Storm Drainage / Riaht- of -Wav
Detention Pond #1 would be located within current public right -of -way. Part of the pond would
be constructed within city owned property while the remainder would lie within the right -of -way
for SR 518. Construction of the facility would require approval of the Washington State
Department of Transportation.
Regional Pond #2 is completely outside City of Tukwila right -of -way, therefore, it would require
acquisition of the site for construction of the facility.
Detention Pond #3 is adjacent to the right -of -way for 42nd Avenue. The building lot is currently
vacant but would require acquisition for facility construction.
Detention Pond #4 lies just north of Southgate Park property. The property is currently
undeveloped. A portion of the site lies within the unopened right -of -way for South 134th Street
but the majority lies to the north. Acquisition of the parcel would be necessary to construct the
detention facility.
ENVIRONMENTAL
An environmental checklist is.being prepared by the City of Tukwila to assess the effects of the
roadway improvements on the natural and human environment, with input by Perteet Engineering,
Inc. Significant changes will, be addressed, such as existing and future traffic, population,
proposed developments, and mitigation. of affected drainage basins. It is anticipated that a
determination of nonsignificant is forthcoming from the SEPA checklist.
42nd Avenue S.E. City of Tukwila
Design Report Page 12
WETLANDS
A reconnaissance investigation of the project site was conducted on July 17, 1991 by Adolfson
Associates, Inc. to determine the extent of wetlands within the anticipated project limits. It was
determined that no wetlands exist within the current right -of -way or immediately adjacent to the
right -of -way. Additionally, investigation of the City of Tukwila wetlands inventory shows no
wetlands listed within the corridor.
UTILITIES
All major utilities are located along the project route, including overhead power, overhead and
buried telephone lines, water, gas, sanitary sewers, and cable television. All utility districts were
contacted during the preparation of the preliminary design to solicit their comments.
Electrical Power
The project site is served by Seattle City Light. Nearly all of the electrical power facilities exist
as overhead power lines. Due to City of Tukwila ordinance, these lines will be removed and
power will be reconstructed as an underground element. The existing underground portions will
require connection to the new facilities and possible relocation or adjustment due to modification
to the vertical or horizontal alignment of the roadway.
Telephone And Cable TV
The project is served by U.S. West Communications and TCI Cablevision for telephone and cable
television service respectively. Throughout the majority of the project, telephone and cable
television lines are located on the same poles as the electrical power. Buried conduits are located
in isolated portions of the project, (primarily to provide service to individual users). The
overhead lines will require undergrounding while the existing underground facilities may require
adjustment or relocation to accommodate the proposed roadway construction.
Natural Gas
Washington Natural Gas provides gas service to the subject project area. From the beginning of
the project at South 160th Street to South 146th Street, a 12 inch high pressure gas line exists on
the east shoulder of the roadway. A four inch and two inch natural gas line also extends through
portions of the project, thus, nearly the entire length of the roadway contains one or more gas
lines. These underground facilities may require relocation or adjustment due to modification of
the existing vertical or horizontal alignment of 42nd Avenue South.
Sanitary Sewer
Major portions of the project contain an existing Val Vue Sewer District sanitary sewer line.
Since a new sewer line was constructed during the late summer /early fall of 1991, current needs
have'been met and no additional sewer facilities are anticipated for this project.
Sanitary sewers exist from approximately 200 feet north of South 160th Street to South 154th
Street, from South 152nd Street to 150 feet south of South 144th Street, and from South 144th
Street to South 130th Street. These facilities are not anticipated to be greatly impacted by the
modifications to the roadway, however, manholes which are located within the roadway prism will
require adjustment to final grade.
42nd Avenue S.E. City of Tukwila
Design Report Page 13
Water System
Water service to the project area is provided by King County Water District No. 125. The entire
route is serviced by a six inch, an eight inch or a twelve inch water main. The water district has
not requested any additional improvements for this project at this time. Minor relocations or
adjustments may be required to accommodate modifications to the vertical or horizontal alignment
of the roadway, including the existing fire hydrants and /or individual services to the adjacent
properties.
A 60 inch water line crosses 42nd Avenue South at South 160th Street. A measurement was made
to determine the clearance to the top of pipe, it is approximately 5.5 feet below existing pavement.
This clearance is adequate for the proposed grade change in this vicinity to improve sight distance.
ILLUMINATION
There is sparse illumination or roadway lighting along the existing roadway of 42nd Avenue South
This project proposes to provide a designed system which will meet todays needs in regard to
safety and operation, considering current and anticipated uses of the facilities by the existing high
school and the residential neighborhood.
The proposed luminaires will be 250 watt, high pressure sodium, cutoff, Type III with a mounting
height of 35 feet. ,Average horizontal foot candle will be 0.6 with a uniformity ratio of 4:1 or
better. Luminaires will be placed on both sides of the roadway.
The proposed luminaires will require their own light standards since it is proposed to underground
the power throughout the project.
PROJECT COST ESTIMATES
Construction cost estimates have been prepared for three possible phases. The first phase is the
section of 42nd Avenue South between South 154th Street and South 139th Street.' The second
phase is the section from South 139th Street to East Marginal Way. The third phase is the section
from South 160th Street to South 154th Street. These phases can be modified to accommodate •
available funding, and estimates are based on values valid for the current time period. Since right -
of -way has not been purchased to accommodate the proposed roadway section, costs would have
to be added for right -of -way acquisition.
PHASE 1 - $2.03 million
PHASE 2 - $1.27 million
PHASE 3 - $0.88 million
42nd Avenue S.E. • City of Tukwila
Design Report Page 14
CITY OF TUKWILA
42ND AVENUE SOUTH
Phase 1
Sta. 72 +00 to Sta. 120+50
Description
Unit
Quantity
Unit
Price
Amount
Mobilization (7 %)
Clearing and Grubbing
Roadway Excavation including Haul
Unsuitable Excavation including Haul
Gravel Borrow including Haul
Pavement Sawing
Crushed Surfacing Base Course
Asphalt Treated Base
Asph. Conc. Pavement, Class B
Asphalt Concrete Driveway
Cement Concrete Curb and Gutter
Cement Concrete Sidewalk
Cement Concrete Approach
Plain Conc. Storm Sewer Pipe 12" Dia
Reinf Conc. Storm Sewer Pipe 24" Dia
Reinf Conc. Storm Sewer Pipe 30" Dia
Corrugated Metal Pipe 36" Dia
Corrugated Metal Pipe 60" Dia
Type I Catch Basin
Type II Catch Basin - 48 In.
Type II Catch Basin - 54 In.
Type II Catch Basin - 60 In
Type 1I Catch Basin - 72 In
Control Structure - 96 In.
Pipe Bedding
Detention Pond/Wetland Planting
Keystone Wall .
Rockery
Galt' Steel Handrail
Signal System
Permanent Signing & Pavement Marking
Traffic Control
Illumination
Miscellaneous Items, 5%
LS
AC
CY
CY
TON
LF
TON
TON
TON
SY
LF
SY
SY
LF
LF
LF
LF
LF
EA
EA
EA
EA
EA
EA
TON
LS
SF
SY
LF
I.S
LS
LS
EA
LS
1
3
4300
4800
12700
4000
1200
4800
4500
3900
9900
4700
800
1870
500
1030
. 20
280
30
3
2
3
1
2
900
1
2800
765
1450
1
1
1
24
1
106,336
3,500
8
12
10
2
15
30
35
14
6
12
16
50
50
60
85
800
1,800
2.300
2,500
5,500
8,000
20
65,000
16
85
45
125,000
15,000
27,000
3,500
72,337
}
$ 106,336
8,750
34,400
57,600
127,000
8,000
18,000
144,000
157,500
54,600
59,400
56,400
17,600
29,920
25,000
51,500
1,200
23,800
24,000
5,400
4,600
7,500
5,500
16,000
18,000
65,000
44,800
65,025
65,250
125,000
15,000
27,000
84,000
72.337
Subtotal 1,625,418
Contingencies @ 25% 406,355
Total Estimated Construction Contract S2,031,773
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CITY OFTUKWILA.
42ND AVENUE SOUTH
Phase 2
Sta 120 +50 to 153 +50
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Description
Unit
Quantity
Una
Price
Amount
Mobilization (7%)
LS
1
66,567
S66,567
Clearing and Grubbing
AC
2.20
3,500
7,700
Roadway Excavation including Haul
CY
2400
8
19,200
Unsuitable Excavation including Haul
CY
--
12
0
Gravel Borrow including Haul
TON
9200
10
92,000
Pavement Sawing
LF
6000
2
12,000
Asphalt Treated Base
TON
900
30
27,000
Asph. Conc. Pavement, Class B
TON
1500
35
52,500
Asphalt Concrete Driveway
SY
2200
14
30,800
Cement Concrete Curb and Gutter
LF
5900
6
35,400
Cement Concrete Sidewalk
SY
2800
12
33,600
Cement Concrete Approach
SY
500
22
11,000
Plain Conc. Storm Sewer Pipe 12" Dia
LF
1620
16
25,920
Plain Conc. Storm Sewer Pipe 18" Dia
LF
490
30
14,700
Type I Catch Basin
EA
20
800
16,000
Type II Catch Basin - 48 In.
EA
2
1,800
3,600
Pipe Bedding
TON
400
20
8,000
Detention Pond/Wetland Planting
LS
1
70,000
70,000
Keystone Wall
SF
7500
16
120,000
Rockery
SY
100
85
8,500
Reinforced Conc. Wall
SF
3500
50
175,000
Galt' Steel Handrail
LF
1450
45
65,250
Permanent Signing & Pavement Marking
LS
1
8,000
8,000
Traffic Control
LS'
1
17,000
17,000 1
Illumination
EA
15
3,500
52,500
Miscellaneous Items, 5% 1
LS
1
45,284
45,284
Subtotal 1,017,520
Contingencies @ 25% 254,380
Total Estimated Construction Contract S1,271,900
CITY OFTUKWILA
42ND AVENUE SOUTH
Phase 3
Sta 50 +00 to 72 +00
'
Description •
Unit
Quantity
Unit
Prix
�I
Amount U
Mobilization (7%)
LS
1
46,271
S46,271
Clearing and Grubbing
AC
1
3,500
3,500
Roadway Excavation including Haul
CY
1700
8
13,600
Unsuitable Excavation including Haul
CY
3500
12
42,000
Gravel Borrow including Haul
TON
6200
10
62,000
Pavement Sawing
LF
2500
2
5,000
Crushed Surfacing Base Course
TON
1200
15
18,000
Asphalt Treated Base
TON
1500
30
45,000
Asph. Conc. Pavement, Class B
TON
1700
35
59,500.
Asphalt Concrete Driveway
SY
1900
14
26,600
Cement Concrete Curb and Gutter
LF
4700
6
28,200
Cement Concrete Sidewalk
SY
2200
12
26,400
Cement Concrete Approach
SY
400
22
8,800
Plain Conc. Storm Sewer Pipe 12" Dia
LF
1785
16
28,560
Reinf Conn Storm Sewer Pipe 24" Dia
LF'
585
50
29,250
Type I Catch Basin
EA
19
800
15,200
Type II Catch Basin - 48 In.
EA
1
1,800
1,800
Type II Catch Basin - 54 In.
EA
3
2,300
6,900
Pipe Bedding •
TON
450
20
9,000
Detention Pond/Wetland Planting
LS
1
70,000
' 70,000
Keystone Wall
SF
2100
16
33,600
Rockery
SY
125
85
10,625
Galv Steel Handrail
LF
800
45
36,000
Permanent Signing & Pavement Marking
LS
1
5,000
5,000
Traffic Control
LS
1
10,000
10,000
Illumination
EA
10
3,500
35,000
Miscellaneous Items. 5%
LS
1
31,477
31.477
Subtotal 707,283
Contingencies @ 25% 176,821
Total Estimated Construction Contract S884.103
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TRAFFIC DATA.
•
x�n. nenmmeaC .•r^i'r.`M!y?,'i'!- '+i7C4Ci!
TRAFFICOUNT
Coat TUKUILA, UA
nAuum. : t2ND AVENUE SOUTH
SOUTH 15LTH
movements or: Primar? DATE: 5i21/91
PAGE: 1
F:LE: TK1.111:A
PEAK PERIOD ANALYSIS FOR THE ?i00: 12:00 FM - U6:00 PM
0Inv..ILON START 'PEAK Ha v0LunE5 tal.:N7B
FROM PEAK HOUR FACTOR PF.05 RiPt Thru Left Tot31 PEDS Ri;mt Thru
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Ent a:30 PM 0.35 • 2 76 275 212 565 1. t= 33
South L:30 ?M 0.55 0 .3 101. 51 200 34. 50 li
Uest 4:15 FM 0.33 1 55 188 16 23? —15 7? 7
Entire intersection
North L:30 PM 0.30
Ent 0.35
South 0.55
'Jest 0.31
[FED. 3
0
0
1
.16
73
68
LO
(12ND
ft
0 313 250 72
250
275
101
166
72
212
31
12
358
565
200
▪ 0 70 20,
11.1 I= 35
3L 50 16
• -
78 5
AVENUE SOUTH tk;=.,i
Pi
. •
WV
......
1 '6
6.0
FED.'S
.35,3
F $ I
2.5 156.7:". rv.
2.
WM:OM
A
1=W
E
20.0
102.
4.2ND AVENUE SOUTH
CP=7"17:
Site Code k%%l.
K-S Street: -4 "1„.„-Lci .
E-W Street:
Weather
• • - •• • t, -,••■•-• •••• ■••••• ..•••••■•••,-,...s.“,■••• .•.•
Perteet Engineering
Primary Movements: Vehicles
PAGE:
FILE:
rz_
DATE: 0
PEAK PERIOD ANALYSIS FOR THE PERIOD: 4:30 PM - 6:30 PM
DIRECTION START PEAK HR VOLUMES .... PERCENTS ...
FROM PEAK HOUR FACTOR Right Thru Left Total Right Thru Left
North 4:30 PM
East 4:30 PM
.South 5:00 PM
West 4:30 PM
Entire Intersection
Worth 4:30 PM
East
South
West
L
12:5
•
■•■•• •••■
••••
1—
Coca : TUKUILA, UA
MANUAL : :7:RO AVE 3
S 1“.TX ST
TRAre....JIAT
1.:vtmtncs bi: Frimary
?AGE: 1
FTLE: U:t317A
DATE: 51:31F1
FEAK',:r.:vu ;NAV!!! F:JF. 7F.F. r:A:uu: 1::G3 Pn - •6:GO .Fr.
01,st.tION START Fig XR voLonEi
FROM FEAX HOUR FACTOR FEGE RiwIt Thru '..tft Total FIG! Rivst Thr• .: Llft
.North .1:00 Fl
East 3:GG PM
South 3:GO FM
:last 5:DO ;II
North FM
East
• South
;;tat
CF-'.EDS 3
G. So •• • 21v I.; 2A4 1: il 17
Cl;:■ :.
vo 7G 63 ...,
.,: ... 1.
u: iG 13
63 1 63. 31! • :G 6: :G
Entirt•Intarc."irn
G.37 i 7: 2G7 3t1
.G.T. 11 ..
.. ii:. 0 .1.
.:-...
..
i 4
:../ .
...1 66 3G3 -
t'• :A
17:,3, •09
6. '2NZ1
• •
AVE 3
1741
• . •
■••••••
•
7 F •
„.„ „.. „ „ - „ - , •-•-• • • • • • !,71,1-•:V.,::
Site Code 1 '- l■
H-S Street:
Street:
Weather
Perteet Engineering
Primary Movements: Vehicles
PAGE:
FILE:
DATE:
:
.1/
. .
■••
•-•
PEAK PERIOD ANALYSIS FOR THE PERIOD: 4:30 PM - 6:30 PM
•DIRECTION START PEAK HR VOLUMES PERCENTS ...
FROM PEAK HOUR FACTOR Right Thru Left Total Right Thru Left
North 4:30 PM
East 4:30 PM
South 5:00 PM
Nest 4:30 PM
North 4:30 PM
East
South
West
"1-)
Entire Intersection
'. 4 ZS
L 03
L
ii:t Coo! TUKt:ILA,
MANUAL : (10TH AVE 5
: 130TH ST -
TRAFFICOUNT
movements by: Primary
?AGE: 1
FILE: TK11,21EF
OATE: 5i2:i91
PEAK FERIOD ANALYSIS FOR THE rtaluo: 1:00 Fl - -.5:30 Fl
Dint.iluN START PEAK MR VOLUMES r:nk.:NTS
Fun FEAK HOUR FACTOR FE05 i;At Thru Left Tote: FEE'S Ricnt-Thru Left
North .1:15 ?3 0.63 5 33 214
15 329
-
Esst 3:15.FM 0.91 2 1 30 75 163 :I 1; :0
South 3:00 FM 0.72 12 25 Si, 33 12 .0
5; 23
Uest 3:15 PM 0.59 1 15 67 2i 1e7 5 SS 12
Entire intersection
North 3:00 FM ' 0.72 7 35 256 ..: 315
Ent •
3.77 1 7 72 5; 133
South 0.72 12 25 81 33 1C,2
Uest . 0.34 1 . 12 53 25 101 _
Cr-Fcis
7
S
2
.3 5
12 &L 3
3 , :
. .13'
13 35 ,;
..
t.: 62 26
12 .'.
25
5
S 30TH ST Inn
SSNSASSNiNiSN.N.:Ni.“.C. N .s$s%nYV!,
CPEos
Perteet Engineering
,
Site Code w lam....:,„ ; =1.��, PAGE:
H -S Street: G, 2,,.,� —1i • FILE:
E -W Street: - =) 0_0". St� , y V\
Weather Primary Movements: Vehicles DATE: 201 e
PEAK PERIOD ANALYSIS FOR THE PERIOD: 4 :30 PM • 6:30 PM
DIRECTION START PEAK HR VOLUMES ... PERCENTS ...
FROM PEAK HOUR FACTOR Right Thru Left Total Right Thru Left
North 4:30 PM
East 4:30 PM
South 5:00 PM
West 4:30 PM
North 4:30 PM
East
South
West
Entire Intersection
a
1
ZZc
W i E
S
r "
227- 1z -lxyve s and s154th st
NAME:42nd ave s
JRLY VOLUMES
Grade 0%
N =2
40
V12
186
1 V11
I I 12
____ 1 1 V10
N= 1 <1 v I>
-ade 07.
31 - -V1
101 --V2
68 - -V3 v
<1 " 1>
V7 1 1
212
V8
N= 2 275
V9
minor road 78
s154th st
Grade 0 %
N
^ V6- 36
V5-- 250 N= 1
V4- 72
major road Grade 0%
42nd ave s
STOP xx
YIELD
Date of Counts:5 /22/91
Time Period:3 /6 pm
Prevailing Speed:35
PHF:90
Population:250000
)LUME ADJUSTMENTS
ovement no. 1 1 1 21 31 41 51 61 71 81 9110111 1121
.,1tcne (vph) 1 311 1011 681 721 2501 361 2121 275. 781 121 1861 401
'11(pcph),Tab.10.11 341XXXXIXXXX1 79IXXXX1XXXX1 2331 3031 861 131 2051 441
•'OLUMEES IN PCPH
44 .
V12
205
1
V11
1 1
1 1
13
V10
<1 v 1> " V6 --
V5 -- -�
34 - -V1 v V4 -- 79
-V2 >
=- - -V3 v <1 ^ 1>
V7 I I
233 1 1 1
V8 1 1
303 'I I
V9 1
86
LCCATION:42nd ave s and s154th st (_ .E:42nd ave s
TEP 1 : RT From Minor Street
/ -> V9
<-1 V12
ronflicting Flows, Vc
_ritical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
— of Cp utilized
mped'ance Factor, P (Fig.10.5)
Actual Capacity, Cm
STEP 2 : LT From Major Street
1/2 V3 +V2 =Vc9
34+ 101= 135 vph.
4.5 (secs.)
Cp9 = 1000 pcph
(V9 /Cp9)x100= 8.6X
P9= .95
Cm9 =Cp9= 1000 pcph
1/2 V6 +VS =Vc12
18+ 250= 268 vph
4.5 (secs.)
Cp12 = 1000 pcph
(V12/Cp12)x100= 4.4X
P12= .97
Cm12 =Cp12= 1000 pcph
v -- V4
V1
Conflicting Flows, Vc
ritical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
% of Cp utilized
mpedance Factor, P (Fig.10.5)
,.ctual Capacity, Cm
V3 +V2 =Vc4
68+ 101= 169 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4/Cp4)x100= 7.9%
P4= .95
Cm4 =Cp4= 1000 pcph
V6 +V5 =Vc1
36+ 250= 286 vph
4.5 (secs.)
Cpl = 1000 pcph
(V1/Cp1)x100= 3.4%
P1= .98
Cm1 =Cp1= 1000 pcph
,TEP 3 : TH From Minor Street V8 v V11
Conflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
:: of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
.5V3 +V2 +V1 +V6 +V5 +V4 =Vc8
34+ 101+ 31+ 36+
250+ 72= 524 vph
5 (secs.)
Cp8 = 691 pcph
(V8/Cp8)x100= 43.8%
P8= .64
Cm8 =Cp8xP1xP4
643= 691x.98x.95pcph
.5V6 +V5 +V4 +V3 +V2 +V1 =Vc11
18+ 250+ 72+ 68+
101+ 31= 540 vph
5 (secs.)
Cp11 = 678 pcph
(V11/Cp11)x100= 30.2%
P11= .77
Cm11= Cp11xP1xP4
631= 678x.98x.95pcph
STEP 4 : LT From Minor Street
< -\ V7
\-> V10
: onflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
'otential Capacity,Cp(Fig10.3)
actual Capacity, Cm
Vc8(step3) +V11 +V12 =Vc7
524+ 186+ 40= 750vph
5.5 (secs.)
Cal = 455 pcph
Cm7 =Cp7xP1xP4xP11xP12
= 455x.98x.95x.77x.97
= 316 pcph
Vc11(step3) +V8 +V9 =Vc10
540+ 275+ 78= B93vph
5.5 (secs.)
Cp10 = 379 pcph
Cm10 =Cp10xP4xP1xP8xP9
= 379x.95x.98x.64x.95
= 215 pcph
:CAT10N:42nd ave s and s154th st
NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR CR LOS LOS.
7VEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM-V) (CSH -V) CM CSH
7. 233 31.6 83 E
8 303 643 698 340 . 309 B 8
9 86 1000 698 914 309 A 8
APPROACH MOVEMENTS 10,11,12
CR CR LOS LOS
!OVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) (CSH -V) CM CSH
10 13 215 202 C
11 205 631 675 426 426 A A
12 44 1000 675 956 426 A A
MAJOR STREET LEFT TURNS 1,4
•MOVEMENT V(PCPH) CM(PCPH) CR(CM-V) LOS
1 34 1000 966 A
4 79 1000 921 A
COMMENTS:
LOCATION:42nd ave s and sCIth st
NAME:42nd; ve s
IOURLY VOLUMES Grade 0%
N= 2
;rade 0%
49 V1
160 --V2
107 --V3
V
63
V12
N = 2
294
V11
I 19
V10
v 1>
N= 2
<1 A
V7
332
V8
435
minor road
5154th st
Grade 0 %
V9
123
N>
V6-- 57
V5-- 395 N= 2
V4-- 114
major road Grade 0%
> 42nd-ave s
STOP xx
YIELD
Date of Counts:201D
Time Period:4/6pm
• Prevailing Speed:35
PHF:90
Population: 250000
yoLumE ADJUSTMENTS
Aovement no.
1 1 1 2 1 3 1 4 1 • 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12
7olume (vph)
1 491 1601 1071 1141 3951 571 3321 4351 1231 191 2941 63.
.7o1(pcph),Tab.10.11 541XXXXIXXXX1 1251XXXXIXXXX1 3651 4791 1351 211 3231 69
JOLUMES IN PCPH
69
V12
54 V1
v
V2
V3
323
V11
21
V10
v 1>
<1
V7
365
V8
479
V9
135
V6-- --
< V5-- --
v V4-- 125
OCATION:42nd ave s and s154th st NAME:42nd ave s
;TEP 1 : RT From Minor Street I / -> V9 < -/ V12
:onflicting Flows, Vc
:ritical Gap, Tc (Tab.10.2)
)ot'ential Capacity,Cp(Fig10.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
'actual Capacity, Cm
STEP 2 : LT From Major Street
:onflicting Flows, Vc V3 +V2 =Vc4
107+ 160= 267 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4 /Cp4)x100= 12.5%
P4= .92
Cm4 =Cp4= 1000 pcph
1/2 V3 +V2 =Vc9
54+ 160= 214 vph
5 (secs.)
Cp9 = 967 pcph
(V9 /Cp9)x100= 14%
P9= .91
Cm9 =Cp9= 967 pcph
1/2 V61-V5 =Vc12
29+ 395= 424 vph
5 (secs.)
Cp12 = 778 pcph
(V12/Cp12)x100= 8.9%
P12= .95
Cm12 =Cp12= 778 pcph
v -- V4 • - -^ V1
:ritical Gap, Tc (Tab.10.2).
' otential Capacity,Cp(Fig10.3)
% of Cp utilized
Impedance Factor, P (Fig.10..5)
lctual Capacity, Cm
V6 +V5 =Vcl
57+ 395=.452 vph
4.5 (secs.)
Cpl = 853 pcph
(V1 /Cpl)x100= 6.3%
P1= .96
Cm1 =Cpl= 853 pcph
';TEP 3 : TH From Minor Street
Conflicting Flows, Vc
V8
v V11
Critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
.5V3 +V2 +V1 +V6 +V5 +V4 =Vc8
54+ 160+ 49+ 57+
395+ 114= 829 vph
5.5 (secs.)
Cp8 = 411 pcph
(V8 /Cp8)x100= 100%
P8= 0
Cm8=Cp8xPlxP4
363= 411x.96x.92pcph
.5V6 +V5 +V4 +V3 +V2 +V1 =Vc11
29+ 395+ 114+ 107+
160+ 49= 854 vph
5.5 (secs.)
Cpll = 398 pcph
(V11 /Cpll)x100= 81.2%
P11= .24•
Cm11= Cp11xP1xP4
352= 398x.96x.92pcph
STEP 4 : LT From Minor Street
< -\ V7
\ -> V10
Conflicting Flows, Vc
:ritical Gap, Tc (Tab.10.2)
2otential Capacity,Cp(Figl0.3)
Actual Capacity, Cm
Vc8(step3) +V11 +V12 =Vc7
829+ 294+ 63= 1186vph
6 (secs.)
Cpl = 209 pcph
Cm7= Cp7xFlxP4xPllxP12
= 209x.96x.92x.24x.95
= 42 pcph
Vcll(step3) +V8 +V9 =Vc10
854+ 435+ 123= 1412vph
6 (secs.)
Cp10 = 153 pcph
Cm10= Cp10xP4xP1xP8xP9
= 153x.92x.96x 0x.91
= 0 pcph
c:.. a. i.r.�,.,.r.::,:a•s�a ✓: ?:.�e'azw, c..cn'c,.•�:..
,0CATION:42nd ave s and s154th st NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR CR LOS LOS
MOVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) (CSH -V) CM CSH
7 365 4.2 -323 F '
8 479 363 421 -116 -193 F F
9 135 967 421 832 -193 A F
APPROACH MOVEMENTS 10,11,12
CR CR LOS LOS"
'0VEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V)•- (CSH -V) CM CSH
10 21 0 -21 F
11 323 352 390 29 -2 , E F
12 69 778 390 • 709 -2 A F
MAJOR STREET LEFT TURNS 1,4
20VEMENT V(PCPH) CM(PCPH) CR(CM -V) LOS
1 54 853 799 A
4 125 1000 875 .A
COMMENTS:
`.'fear 2011
INPUT WORKSHEET
Intersection:] t
Analyst:jc Time ?eriod Anlyzd:4 /6pm
Project No.91256] City /State:tukwila wa
Date:2010
Area Type: CBD XOther
VOLUME AND GEOMETRICS
1
1
(N)
111
NORTH
IDENTIFY IN DIAGRAM
1.Volumes
2.Lanes,lane widths
42nd ave s N/S ST.
( 566] 123 "
SB TOTAL 1 1
1 I I 12.0 I
< v > I 12.0
57 395 114 RTH LT
< >
, v < " -- RTH - 12.0' -1
v--- LT-12.0' -1
1-12.0' -LT --
435 <- [ 893]
-WB TOTAL
335 v
1-12.0'- RTH--v>
3.Movements by lane " 19
4.Parking locations -
5.Bay storge ingths 1 376] -> 294
6- Islands E/8 TOTAL -
7.Bus stops v 63
TRAFFIC AND ROADWAY CONDITIONS
< >
LT RTH
12.0 1
1 12.0
1 1
s154th st
E/W STREET
160
49 <^> 107
( 316]
N/B TOTAL
AplGrd.1 % HV Adj.Pkg.Lane Buses PHF
prl (%)I Y/N Nm • (Nb)
-- I- - -- I
881 +0.01 10.0 N 0 0 0.00
WBI +0.0I 10.0 N 0 0 0.00
NBI+0.0I 10.0 N 0 0 0.00
SBI +0.01 10.0 N 0 .0 0.00
Cnf.Ped
(pd /hr)
0
0
0
0
Pedstrn Button
Y/N Mn.Time
N
N
N
N
12
12
12
12
Arr.
Type
3
3
3
3
Grade : +up, -down Nb:buses stopping /hr Min.Timing: min.green for
HV:veh. > 4 whls PHF:peak-hour factor pedestrian crossing
Nm:pkg.maneuvers /hr Cnf.Peds:Cnflctng peds /hr Arr.Type: Type 1 -5
PHASING
D
1 < * * * **
A + 0000>
G v oo"
R <0000 +
A *>
M
Tim-
ing
v
G= 0.0
Y +R= 0
Ptmd /Actl A
*
* 000
v
000 *
v *
G= 0.0
Y +R= 0
A
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
Protected turns:
0000^ 1 Permitted turns: +++ +" 1 Cycle Length 70 Sec
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
Intersection:i 5 ` r4L 4^-%
Analyst:jc TimePeriod Anlyzd:4 /6pm
Project No.91256] City /State:tukwiia wa
__---_ _______ • °___= _______ =___ = = = =___ = = = = =__
Date:2010
Area Type: C8D XOther
LANE GROUP
1
Appr.
2
Mvmt.
3
Adjusted
Flow Rate
v
(vph)
CAPACITY ANALYSIS WORKSHEET
4
Ad.Sat
FIW.Rt
s
(vphg)
5
Flow Ratio
v/s
3/4
6
Green
Ratio
g / C
E8
WB
'118
SB
H
H
H
H
439 -
1042 -
369 -
660 -
2469
2755
2612
3080
0.178
0.378
0.141
0.214
0.584
0.584
0.331
0.331
7 I 8
Ln.Grpl v/C
Capac.I Ratio
c,vph I X
4x6 I 3/7
1441
1608
864
1018
0.305
0.648
0.427
0.648
9
Crit.
Lane
Group
* * *
Cycle Length= 70.0sec, Lost Time /Cycie,L= 6.0sec, S(v /s)ci= 0.593, Xc =0.648
LANE GROUP DIAGRAMS -( * ** = PROTCTD, '++* = PERMTTD, #4# = PROTCTD & PERMTTD]
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
llntersection:0
'Analyst:lc
'Project No.91256)
1.
I First Term Delay
LANE 3 4 I 5 6
GROUP v/c Greenl Cycle Delay
Ratio RatiolLength d1
1 12 'X g/C l C sec /veh
ApIMv I (sec)
1
EBI H
Date:201C>
TimePeriod Anlyzd:4 /6pm Area Type: CBD XOtherI
City /State:tukwila wa 1
= = 1
LEVEL-OF- SERVICE WORKSHEET
Second Term Delay Tot.Delay_ LOS
7 I 8 I 9 10 11 12 13
Lane' Delay IPrgrsn Lane Gp Ln Apprch Apr
Group' d2 'Factor Delay Gp Delay LOS
Cap,clsec /vehl PF sec /veh LOS sec /veh Tbl
(vph)I IT.9 -13 (6+8) *9 9 -1 9 -1
= ==.1= = =a == =1 = - - - -- = = = == = =1` _ _ ---
- -- �
1 1
14411 0.041 0.85 4.80 A 4.80 A
1 1 1
1 1 1
1 1
0.5841 70.0 7.42 16081 0.661 0.85 6.86 8 6.86 6
1 1 1
1 1 1
1 1 1
0.3311 70.0 13.88 864' 0.221 0.85 11.98 B 11.98 8
1 1 1
1 1 1
1 1 1
0.3311 70.0 15.17 10181 1.031 0.85 13.77 8 13.77 8
'I 1 1
1
'WEI H
NBI H
0.305
0.648
0.427
0.648
_ 1=
1
0.584I 70.0 5.61
Intersection Delay 9.07 sec /veh, Intersection LOS 8 Table 9.1
LANE GROUP DIAGRAMS-[* ** = PROTCTD, +++ = PERMTTD, #4# = PROTCTD & PERMTTD)
H
*
v
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
INPUT WORKSHEET
IIntersection:S. 154th Street at 42nd Ave. S
IAnalyst:rlp
Project No.91256 -00 City /State:Tukwila
Date:18 2 7 1 ZCv IO
TimePeriod Anlyzd:pm peak Area Type: CBD XOther
'VOLUME AND GEOMETRICS
I: •
A
(N)
NORTH
(IDENTIFY IN DIAGRAM
11.Votumes
2.Lanes,lane widths
3.Movements by lane
(4.Parking locations
15.Bay storge ingths
6.lstands
c7.Bus stops
(TRAFFIC AND ROADWAY CONDITIONS
ApIGrd.j % RV' Adj.Pkg.Lane
"Iprj (%)j Y/N Nm
j- - j - -- -j
`EBj +4.01 2.0
.WB1-4.0I 2.0. N
[NB( -2.01 2.0 N
ISBj +2.0j 2.0 N
42nd Avenue N/5 ST.
( 545]
SB TOTAL
1 1 1
< v >
36 395 114
1-12.0'- LT - - -^
11.0
TH
1-12.0'- RTH--v>
( 3763
E/B TOTAL
^ 19
-> 294
v 63
(
v
123^
435 <- [ 893]
-WB TOTAL
335 v
< "-- RTH-12.0"-1
v--- LT-12.0' -1
TN
11.0
154th Street
E/W STREET
160
49 <^> 107
[ 316]
N/8 TOTAL
0
0
0
0
Buses
(Nb)
0
0
0
0
PHF
0.90
0.90
0.90
0.90
Cnf.Ped
(pd /hr)
10
10
10
10
Pedstrn Button
Y/N Mn.Time
N
N
N
N
8
8
12
12
Arr.
Type
3
3
3
3
Grade : +up, -down
JHV:veh. > 4 whls
'Nm :pkg.maneuvers /hr
Nb:buses stopping /hr Min.Timing: min.green for
PHF:peak -hour factor pedestrian crossing
Cnf.Peds:Cnflctng peds /hr Arr.Type: Type 1 -5
'PHASING
1
..1
j
..i
ITim-
ing
-1Ptmd /Act' A
(
i Protected
D
A
G
R
A
M
^
v
A
v
G= 22.1
Y +R= 3
*
G= 31.9
Y +R= 3
A
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
turns:
0000^ j Permitted turns: + + + +^ j Cycle Length 60 Sec
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
Intersection:S. 154th Street at 42nd Ave. S Date:10 /28/91
Analyst:rlp TimePeriod Anlyzd:pm peak Area Type: CBD XOther
Project No.91256 -00 City /State:Tukwila
VOLUME ADJUSTMENT WORKSHEET
_ _- -_ _
1 2 3 4 5 6 7 8 9 10. 11
Appr. Mvt. Mvt. Peak Flow Lane flu rt Number Lane Adj. Prop.
Volume Hour Rate Group in Ln of Utiliz Flow of
(vph) Factor Vp Grp Vg Lanes Fctr,U V,vph LT or RT
PHF 3/4 (vph) N Tb 9 -4 7 x 9 Plt , Prt
LT 19 0.90 21 A 21 1 1.00 21 1.00 LT
EB TH 294 0.90 327 N 397 1 1.00 397 *
RT 63 0.90 70 0.18 RT
LT 335 0.90
WB TH 435 0.90
RT 123 0.90
LT 49 0.90
NB TH 160 0.90
RT 107 0.90
LT 114 0.90
SB TH 395 0.90
RT 36 0.90
(LANE GROUP DIAGRAMS -C * **
A A I^ I N
* + 1
* * ** I * * **> I * * * *,
v
372 A 372 1 1.00 372 1.00 LT
483 N 620 1 1.00 620 *
137 0.22 RT
54 0.15 LT
178 I 351 1 1.00 351 *
119 0.34 RT
127 0.21 LT
439 I 606 1 1.00 606 *
40 0.07 RT
= PROTCTD, + ++ = PERMTTD, #4V1 = PROTCTD & PERMTTD]
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
<�,
.ntersection:S. 154th Street at 42nd Ave. S Date:10/28/91
:nalyst:rlp TimePeriod Anlyzd:pm peak Area Type: CBD XOther
'roject No.91256 -00 City /State:Tukwila
SUPPLEMENTAL WORKSHEET FOR LEFT -TURN ADJUSTMENT FACTOR, fLT
INPUT_VARIABLES /COMPUTATIONS
Cycle Length, C (sec)
Effective Green, g (sec)
Number of Lanes, N
Total Approach Flow Rate, Va(vph)
Mainline Flow Rate, Vm (vph)
Left-Turn Flow Rate,,Vlt (vph) .
Proportion of LT, Plt
Opposing Lanes, No
Opposing Flow Rate, Vo (vph)
Prop. of LT in Opp. Vol. Plto
.Sop = 1800No /(1 +Plto[(400 +Vm)etc.
Yo = Vo /Sop
Gu = (g- CYo) /(1 -Yo)
;Fs = (875- 0.625Vo)/1000
Pl = Plt[1 +(N-1)g /(FsGu+4.5)3
Gq = g - Gu
iPt = 1 - Pl
IGf = 2PtIl- Pt^(.S6q)3 /Pl
'El =, 1800/(1400 -Vo)
Fm = Gf /g + Gu /g * [1/(1 +P1 etc.
Flt = (Fm + N - 1) /N
EB
WB
NB_
60.00
31.85
1
351
297
54
0.15
1
479
0.21
1590
0.301
19.71
0.576
0.154
12.14
0.846
7.010
1.954
0.832
0.832
S8_
60.00
31.85
1
606
479
127
0.21
1
297
0.15
1570
0.189
25.28
0.689
0.210
6.57
0.790
4.059
1.632
0.904
0.904
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
Intersection:S. 154th Street at 42nd Ave. S Date:10/28/91
lAnalyst:rlp TimePeriod Anlyzd:pm peak Area Type: CBD XOther
'Project No.91256-00 City/State:Tukwila
CAPACITY ANALYSIS WORKSHEET
=
1LANE GROUP
1
lAppr.
•
EB
WB •
NB
SB
2
Mvmt.
A
H
A
N
3
Adjusted
Flow Rate
v
(vph)
21 -
397 -
372 -
620. -
351 -
606 -
4
Ad.Sat
Flw.Rt
s
(vphg)
======
1659
1699
1727
1755
1239
1378
5
Flow Ratio
v/s
3/4
==
0.013
0.234
0.215
0.353
alb
0.283
0.440
6 7 8
Green Ln.Grp v/C
Ratio Capac. Ratio
g / C c,vph X
4x6 3/7
=
0.369 612 0.034
0.369 627 0.633
0.369
0.369
•
0.531
0.531
9
Crit.
Lane
Group
637 0.584
648 0.957
658
732
0.534
0.828
= -
***
* * *
Cycle Length= 60.0sec, Lost Time/Cycle,L= 6.0sec, S(v/s)ci= 0.793, Xc=0.881
LANE GROUP DIAGRAMS-E*** = PROTCTD, +++ = PERMTTD, 441 = PROTCTD & PERMTTD]
A I N 1
+
**** ***** ****>
+ 1 + 1
v 1 y
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
Intersection :S. 154th Street at 42nd Ave. S Date:10 /28/91
Analyst:rlp TimePeriod Anlyzd :pm peak Area Type: CBD XOtherl
?roject No.91256-00 City /State:Tukwila
1
LEVEL-OF- SERVICE WORKSHEET
First Term Delay Second Term Delay 1Tot.Delay_& L0S
ANE 3 4 1 5 6 7 1 8 1 9 10 1 11 12 1 13
ROUP v/c Green Cycle Delay Lane Delay 1Prgrsn Lane Gpl Ln ApprchlApr
- - -- Ratio RatiolLength d1 Group d2 !Factor Delay 1 Gp Delay 1LOS
2 X g/C 1 C sec /veh Cap,c1sec /veh PF sec /veh1LOS sec /vehlTbl
p1Mv 1 (sec) (vph)) 1T.9 -13 (6 +8) *919 -1 19 -1
=1 -- 1 1 1 1 - -- 1 - --
1 A 0.034 0.3691 60.0 9.19 6121 0.001 1.00 9.191 B
31 N 0.633 0.3691 60.0 11.84 6271 1.481 0.85 11.331 B 11.221 8
1 1 1 1 1 1
-1-- 1.__ l__.
1 A 0.584 0.3691 60.0 11.57 6371 1.021 1.00 12.581 B
al N 0.957 0.3691 60.0 14.03 6481 18.441 0.85 27.601 D 21.971 C
1 1 1 1 1 1
1 1 1 1 1 1
SI I 0.534 0.5311 60.0 7.00 6581 0.681 0.85 6.531 B 6.531 B
1 1 1 1 1 1
1 1 1 1 1 - -- 1 - --
•8' I 0.828 0.5311 60.0 8.95 7321 5.501 0.85 12.291 8 12.291 B
1 1 1. 1 1 1
Intersection Delay 15.30 sec /veh, Intersection LOS C Table 9.1
.LANE GROUP DIAGRAMS-I * ** = PROTCTD,
+ ++
= PERMTTD, # ## = PROTCTD & PERMTTD]
A A I ^ N
* +
* * ** * * * *> I * * * *>
+1 +1
.v J v j
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
*JOCATION:42nd ave s and s144th st
NAME:42nd ave s
HOURLY VOLUMES Grade 0%
1
Grade 0%
N= 1
52 --V1
72 --V2
50 --V3
65
V12
N = 1
178
V11
1 66
1 V10
v 1>
<1 A
V7
47
V8
N= 1 163
V9
minor road 22
s144th st
Grade 0 %
V
N>
V6-- 74
V5-- 207 N= 1
V4-- 34
major road Grade 0%
42nd ave s
STOP xx
YIELD
Date of Counts:5/23/91
Time Period:4/6pm
Prevailing Speed:35
PHF:90
Population: 250000
:70LUME ADJUSTMENTS
!lovement no. 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1,8 1 9 1 10 1 11 1 12
volume (vph) 1 521 721 501 341 2071 741 471 1631 221 661 1781 65
'Tol(pcph),Tab.10.11 571XXXX1XXXX1 371XXXXIXXXX1 521 1791 241 731 1961 72
7OLUMES IN PCPH
72
V12
57 7-V1 A
== --V2
V3
196
V11
1 73
V10
v 1>
<1
V7
52
•
V8
179
V9
24
V6-- --
<
V5-- --
v V4-- 37
�OCATI0N:42nd ave s and $:._44th st
NPME:42no,._ave s
STEP 1 : RT From Minor Street
1-> V9
< -/ V12
:onflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
1/2 V3 +V2 =Vc9
25+ 72= 97 vph
5 (secs.)
Cp9 = 1000 pcph
(V9 /Cp9)x100= 2.4%
P9= .99
Cm9 =Cp9= 1000 pcph
1/2 V6TV5 =Vc12
37+ 207= 244 vph
5 (secs.)
Cp12 = 938 pcph
(V12 /Cp12)x100= 7.7%
P12= .95
Cm12 =Cp12= 938 pcph
STEP 2 : LT From Major Street v -- V4 - V1
:onflicting Flows, Vc
^,ritical Gap, Tc (Tab.10.2)
'otential Capacity,Cp(Fig10.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
actual Capacity, Cm
V3 +V2 =Vc4
50+ 72= 122 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4 /Cp4)x100= 3.7%
P4= .98
Cm4 =Cp4= 1000 pcph
V6 +V5 =Vc1
74+ 207= 281 vph
4.5 (secs.)
Cpl = 1000 pcph
(V1 /Cpl) x100= 5.7%
P1= .97
Cml =Cpi= 1000 pcph
>TEP 3 : TH From Minor Street
V8
v V11
Conflicting Flows, Vc
critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
of Cp utilized
Empedance Factor, P (Fig.10.5)
Actual Capacity, Cm
.5V3 +V2 +V1 +V6 +V5 +V4 =Vc8
25+ 72+ 52+ 74+
207+ 34= 464 vph
5.5 (secs.)
Cp8 = 652 pcph
(V8 /Cp8)x100= 27.5%
P8= .79
Cm8= Cp8xPlxP4
620= 652x.97x.98pcph
• 5V6+V5 +V4+V3+V2 +V1 =Vc1_
37+ 207+ 34+ 50+
72+ 52= 452 vph
5.5 (secs.)
Cpll = 661 pcph
(V11 /Cell) x100= 29.7%
P11= .77
Cm11= Cp11xP1xP4
628= 661x.97x.98pcph
STEP 4 : LT From Minor Street
< -\ V7
\ -> V10
',:onflicting Flows, Vc
'.ritical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
Actual Capacity, Cm
Vc8(step3) +V11 +V12 =Vc7
464+ 178+ 65= 707vph
6 (secs.)
Cpl = 411 pcph
Cm7= Cp7xPlxP4xP11xP12
= 411x.97x.98x.77x.95
= 286 pcph
Vcll(step3) +V8 +V9 =Vc10
452+ 163+ 22= 637vph
6 (secs.)
Cp10 = 456 pcph
Cm10= Cp10xP4xP1xP8xP9
= 456x.98x.97x.79x.99
= 339 pcph
0CATION:42nd ave s and s144th st NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR .CR LOS LOS
MOVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM-V) (CSH-V) CM CSH
.
• 52 286 516 234 261 C C
8 179 620 516 441 261 A C
9 24 1000 516 976 261 A C
APPROACH MOVEMENTS 10,11,12
CR CR LOS LOS
.10VEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM-V) - (CSH-V) CM CSH
?..
10 73 339 564 266 223 C C
• 11 196 628 , 564 432 223 . A C
: 12 72 938 564 866 223 A C
MAJOR STREET LEFT TURNS 1,4
.10VEMENT V(PCPH) CM(PCPH) CR(CM-V)
LOS
1
4
COMXENTS:
year 1991,
.57 1000
37 1000
943
963
A
A
LOCATION: 42nd ave s and s1 .44th st
OURLY VOLUMES
Grade 0%
•
•
•
•
N= 2
82 - -VI
114 - -V2
79 - -V3
NAME : 42nd.ave s
Grade 0%
v
103
V12
N = 1
281
V11
I 104
V10
v 1>
<1
V7
74
N= 1
A
VS
258
minor road
s144th st
Grade 0 %
V9
35
N>
V6 -- 117
, .V5 327 N= 2
v V4 -- 54
major road Grade o%
> 42nd'ave s
STOP xx
YIELD
Date of Counts:201D
Time Period:4 /6pm
Prevailing Speed:35
PHF:90
Population: 250000
VOLUME ADJUSTMENTS
!ovement no. 1 1 2, 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 ;
Volume (vph)
1 821 1141 791 541. 3271 .1171 741 2581 351 1041 2811 103
!Tol(pcph),Tab.10.11 901XXXX1XXXX1 591XXXXfXXXX' 811 284' 39+ 1141 3091 113
iOLUMES IN PCPH
90 - -V1
__ - -V2
__ ---V3
113
V1.2
v <1
V7 I81
V8
284
V9
39
v
V6 -- =-
V5-- ==
V4 -- 59
OCATION:42nd ave s and s144th st NAME:42nd ave s
--------- - - - - -- - ---------------------------------------- - - - - --
:TEP 1 : RT From Minor Street I / -> V9
:oriflicting Flows, Vc
.ritical Gap, Tc (Tab.10.2)
'ot,ential Capacity,Cp(Figl0.3)
of Co utilized
impedance Factor, P (Fig.10.5)
.ctual Capacity, Cm
1/2 V3 +V2 =Vc9
40+ 114= 154 vph
5 (secs.)
Cp9 = 1000 pcph
(V9 /Cp9)x100= 3.9%
P9= .98
Cm9 =Cp9= 1000 pcph
< -/ V12
1/2 V6 +V5 =Vc12
59+ 327= 336 vph
5 (secs.)
Cp12 = 812 pcph
(V12 /Cp12)x100= 13.9%
P12= .91
Cm12 =Cp12= 612 pcph
;TEP 2 : LT From Major Street
:: onflicting Flows, Vc
v -- V4
- V1
.ritical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
% of Cu utilized
:mpedance Factor, P (Fig.10.5)
actual Capacity, Cm
V3 +V2 =Vc4
79+ 114= 193 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4 /Cp4)x100= 5.9%
P4= .96
Cm4 =Cp4= 1000 pcph
V6 +V5 =Vc1
117- 327= 444 vph
4.5 (secs.)
Cpl = 860 pcph
(V1 /Cpl) x100= 10.5%
P1= .94
Cml =Cpl= 860 pcph
;TEP 3 : TH From Minor Street
V8
v V11
Conflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
of Co utilized
impedance Factor, P (Fig.10.5)
?ctual Capacity, Cm
.5V3 +V2 +V1 +V6-=V5 +V4 =Vc8
40+ 114+ 82+ 117+
327+ 54= 734 vph
5.5 (secs.)
Cp8 = 465 pcph
(V8 /Cp8)x100= 61.1%
P8= .47
Cm8= Cp8xP1xP4
420= 465x.94x.96pcph
.5V6 +V5 +V4 +V3 +V2 +V1 =Vc_
59+ 327+.54+ 79-
114+ 82= 715 vph
5.5 (secs.)
Coll = 476 pcph
(V11 /Cpll) x100= 64.9%
P11= .43
Cm11= Cp1lxPl x?4
430= 476x.94x.96ocoh
STEP 4 . LT From Minor Street
< -\ V7
\ -> V10
Conflicting Flows, Vc
itical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
Actual Capacity, Cm
Vc8(step3) +V11 +V12 =Vc7
734+ 281+ 103= 1118vph
6 (secs.)
Cpl = 230 pcph
Cm7= Cp7xPlxP4XPl1xP12
= 230x.94x.96x.43x.91
= 81 pcph
Vcll (step3) +V8 +V9 =Vc1C
715+ 256+ 35= 1008vph
6 (secs.)
Cpl0 = 272 pcph
Cm10= CplOxP4xPlxP8xP9
= 272x.96x.94x.47x.98
= 113 pcph
,OCATION:42nd ave s and s144th st
NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR CR LOS LOS
MOVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) (CSH -V) CM CSH
7 81 81 236 0 -168 E F •
8 284 420 236 136 -168 D F
9 39 1000 236 961 -168 A F
•
APPROACH MOVEMENTS 10,11,12
CR CR . LOS LOS
110VEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) - (CSH -V) CM CSH
10 114 113 287 -1 -249 F F
11 309. 430 287 121 -249 . D F
. 12 113 812 287 • 699 -249 A F
MAJOR STREET LEFT TURNS 1,4
.40VEMENT V(PCPH) CM(PCPH) CR(CM -V). LOS
1 90 860 770 A
4 59 1000 941 A
.. COMMENTS:
2011
Intersection:42nd
Analyst:jc
Project No.91256
......
INPUT WORKSHEET
ave s and s1L4th st
TimePeriod Anlyzd:4/6 pm
City /State:tukwila ua
VOLUME AND GEOMETRICS
1
1
(N)
iii
NORTH
• IDENTIFY IN DIAGRAM
1.Volumes
2.Lanes,lane widths
Date:201G
Area Type: C30 )(Other
____ ==
42nd ave s N/S ST.
[ 498]
S3 TOTAL
1 1 1
< v >
117 327 54
1-12.0' -LT - --
1 1
12.0
1 12.0
RTH LT
< >
v
1-12.0'- RTH - -v>
3.Movements by lane ^ 104
4.Parking locations
S.Bay storge ingths [ 488] -> 281
6.Islands E/B TOTAL
7.Bus stops v 103
TRAFFIC AND ROADWAY CONDITIONS
35^
253 <- [ 367]
-WB TOTAL
74 v
< ^--RTH - 12.0' -1
v--- 1T- 12.0 -1
< >
LT RTH
12.0
12.0
1 1
s144th sz
E/W STREET
114
82 <^> 79
[ 275]
N/3 TOTAL
AplGrd.1 % HV
pr (:.)
-- 1-- - -1
E31+0.01 2.0
W81+0.01 2.0
N81 +0.01 2.0
531 +0.01 2.0
Adj.Pkg.Lane
Y/N Nm
N
N
N
N
0
0
0
0
Buses
(Nb)
0
0
0
0
PHF Cnf.Ped Pedstrn Sutton Arr.
(pd /hr) Y/N Mn.Time Type
0.90 0 N 12 3
0.90 0 N 12 3
0.90 0 N 12 3
0.90 0 N 12 3
Grade: +up, -down Nb:buses stopping /hr Min.Timing: min.green for
HV:veh. > 4 whls PHF:peak-hour fac :or pedestrian crossing
Nm:pkg.maneuvers /hr Cnf.Peds:Cnflctng peels /hr Arr.Type: Type 1-5
PHASING
D
I
A
G
R
A
M
Tim-
ing
*
v o ^
<0000 +
*
v
G= 0.0
Y +R= 0
Ptmd /Actl A
*
* 000
v
000. *
✓ *
G= 0.0
Y +R= 0
A
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
G= 0.0
Y +R= 0
Protected turns: 0000^ 1 Permitted turns: +-+ +^ 1 Cycle Length 70 Sec
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
.�'fT4*x�:.W+.... wt•' s� +s.4ts:fxs•�•:.:,�it...uC•S:;hY •.rnc,vnw.
...f,.+r.,nr_.�.... ,Mr.•�rn..tu,+wsN?w afY` twe. ris,. in•-1 tmv: r., F, wuWts:[`.+ s. R,YW:•• /x,.[s.vnw}.td'�aysWS�n.
Intersection:42nd
Analyst:jc
Project No.91256
ave s and s144th st
TimePeriod Anlyzd:4 /6 pm
City /State:tukwila wa
_ =_
_
_
ii
Oate201O
Area Type: C30 XOther
CAPACITY ANALYSIS WORKSHEET
_ =__ == = =___ =__ =_ _ =____=___
LANE GROUP 3
Adjusted
1 2 Flow Rate
Appr. Mvmt. v
(vph)
E3
UB
NB
sa
==
H
H
N
H
569 -
428 -
321
581 -
4
Ad.Sat
FLW.Rt
s
(vphg)
_ -°
2908
5
Flow Ratio
v/s
3/4
6
Green
Ratio
g / C
= = = = = ==
7 l 8
Ln.Grp v/C
Capac. Ratio
c,vph X
4x6 1 3/7
2759
2590
3262
0.196
0.155
0.124
0.178
0.479
0.479
0.436
0.436
1392
1321
1128
r
.1421
9
Crit.
Lane
Group
0.409
0.324
0.284
0.409
ewe
Cycle Length= 70.0sec, Lost Time /Cycle,L= 6.0sec, S(v /s)ci= 0.374, Xc =0.409
LANE GROUP DIAGRAMS -(*'• = PROTCTD, +++ = PERMTTD, t#44 = PROTCTO & PERMIT())
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI'
1Intersection:42nd ave s and s144th st
lAnalyst:jc TimePeriod Anlyzd:4 /6 pm
'Project No.91256 City /State:tukuila wa
1
LANE
GROUP
. 1
Ap
2
My
Date:2010 1
Area Type: C30 XOtherl
LEVEL-OF- SERVICE WORKSHEET
First Term Delay
3 4 1 5 1 6
v/c Green( Cycle! Delay
Ratio RatiolLengthl d1
X g/C 1 C 'sec /veh
1 (sec)(
E3
W8
N8
SB
H
H
H
N
0.409
0.324
0.284
0.409
1 1
1 1
0.4791 70.01 8.99
• 1 1
1 1
1 1
0.4791 70.01 8.56
1 1•
I 1
1 1
0.4361 70.01 9.67
1 1
1 1
1 1
0.4361 70.01 10.31
1 1
Second Term Delay Tot.Delay b LOS
7 1 8 1 9 10 11 12 13
Lane!. Delay 1Prgrsn Lane Gp Ln Apprch Apr
Group' d2 'Factor Delay Gp Delay LOS
Cap,clsec /veh( PF sec /veh LOS sec /veh Tbl
(vph)1 (7.9 -13 (6 +8)'9 9 -1 9 -1
1
13921 0.111 0.85 7.74 8 7.74 8
1 1
1 1
1 1
13211 0.051 0.85 7.32
1
1 1
1
11281 0.041 0.85 8.25
1 1
'1 1
1 ( .
14211 0.111 0.85 8.86
1 1
8
8
8
7.32
8.25 8
8.86
8
Intersection Delay 8.07 sec /veh, Intersection LOS 8 Table 9.1
LANE GROUP DIAGRAMS -( "' = PROTCTD, +++ = PERMTTD, # = PROTCTD 3 PERMTTD]
H ^1
1
yr
V
PERTEET ENGINEERING, Everett, Washington, using NCAP by PSI
1,0CATION:42nd ave s and s.30th st
NAME:42na—ave s
HOURLY VOLUMES
Grade 0%
• 12
V12
N= 2
•
:-.=rade 0%
33 --V1
84 --V2
25 --V3
N = 2
63
V11
I 26
V10
v 1>
v <)
V7
I •
59
V8
N=2 72 •
V9
minor road 7
s130th st
Grade 0 %
V6-- 38
-V5-- 266 N= 2
v V4-- 11
major road Grade 0%
> 42nd ave s
STOP xx
YIELD
Date of Counts:5/22/91
Time Period:4/6pm
Prevailing Speed:35
PHF:90
Population: 250000
..VOLUME ADJUSTMENTS
• -
Movement no. 1 1121314.1516 718191101111 12 1
:Volume..(vph)
1 331 84) 25) 11) 2661 38) 59) 72) 7) 26) 63) 121
yo1 (pcph),Tab.10.11 361XXXXIXXXX1 121XXXXIXXXX1 .651 79) 8) 29) 691 13!
VOLUMES IN PCPH
36 V1
-- --V2
--V3
A
13
V12
69
V11
1 29
V10
v
v. <1
V7
65
V8
79
V9
8
A V6-- --
< V5-- ==
v. V4-- 12
_OCATION:42nd ave s and s130th
st
NAME:42nd ave s
;TEP 1 : RT From Minor Street
1-> V9
< -/ V12
: onflicting Flows, Vc
2ritical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
kctual Capacity, Cm
1/2 V3 +V2 =Vc9
13+ 84= 97 vph
5 (secs.)
Cp9 = 1000 pcph
(V9 /Cp9)x100= .8%
P9= 1
Cm9 =Cp9= 1000 pcph
1/2 V6 +V5 =Vc12
19+ 266= 285 vph
5 (secs.)
Cp12 = 899 pcph
(V12 /Cp12)x100= 1.4%
P12= .99
Cm12 =Cp12= 899 pcph
---- - - - - --
STEP 2 : LT From Major Street v -- V4 ( - -^ V1
2onf licting Flows, Vc
Critical Gap, Tc (Tab.10.2)
? otential Capacity,Cp(Figl0.3)
of Cp utilized
Impedance Factor, P (Fig.10.5)
?actual Capacity, Cm
V3 +V2 =Vc4
25+ 84= 109 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4 /Cp4)x100= 1.2%
P4= .99
Cm4 =Cp4= 1000 pcph
V6 +V5 =Vc1
38+ 266= 304 vph
4.5 (secs.)
Cpl = 996 pcph
(V1 /Cpl)x100= 3.60
P1= .98
Cm1 =Cp1= 996 pcph.
STEP 3 : TH From Minor Street
Conflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
% of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
^ V8
.5V3 +V2 +V1 +V6 +V5 +V4 =Vc8
13+ 84+ 33+ 38+
266+ 11= 445 vph
5.5 (secs.) •
Cp8 = 666 pcph
(V8 /Cp8)x100= 11.9%
P8= .92
Cm8= Cp8XPlxP4
646= 666x.98x.99pcph
v V11
.5V6 +V5 +V4 +V3 +V2 +V1 =Vc1.
19+ 266+ 11+ 25+
84+ 33= 438 vph
5.5 (secs.)
Cpll = 672 pcph
(V11 /Cpll) x100= 10.3%
P11= .94
Cm11 =Co l lxP 1xP4
652= 672x.98x.99pcph
STEP 4 : LT From Minor Street
< -\ V7
\ -> V10
Conflicting Flows, Vc
-.Critical Gap, Tc (Tab.10.2.)
Potential Capacity,Cp(Fig10.3)
Actual Capacity, Cm
Vc8(step3) +V11 +V12 =Vc7
445+ 63+ 12= 520vph
6 (secs.)
Cpl = 536 pcph
Cm7= Cp7xPlxP4xPl1xP12
= 536x.98x.99x.94x.99
= 484 pcph
Vcll(step3) +V8 +V9 =Vc1C
438+ 72+ 7= 517vph
6 (secs.)
Cp10 = 538 pcph
Cm10= CplOxP4xP1xP8xP9
= 538x.99x.98x.92x 1
= 480 pcph
..,4.:vA nrk•nr.. S:`)E:Y3^.:: ;°.+i'`.�.:}3:ws'�t5: tin In i`,4�.�'i tl �x`•hrt�,,`
,OCATION:42nd ave s and s130th st NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR CR LOS LOS
MOVEMENT V(PCPH) CM(PCPH) CSH(PCPH), (CM -V) (CSH -V) CM CSH
7 65 484 419 A
8 79 646 668 567 581 A A
9 8 1000 668 992 581 A A
APPROACH MOVEMENTS 10,11,12
CR CR LOS LOS
- OVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) (CSH -V) CM CSH
10 29 480 451 A
11 69 652 682 583 600 . A A
12 13 899 682 • 886 600 A A
MAJOR STREET LEFT TURNS 1,4
-. IOVEMENT V(PCPH) CM(PCPH) CR(CM -V) LOS
•
r
•
1
36 996
4 12 1000
COMMENTS:
960
988
A
A
L
OCATION:42nd ave s and s130th st NAME:42nd ave s
.OURLY VOLUMES Grade 0%
;rade 0%
N= 2
52 --V1
133 --V2
40 --V3
19
V12
N = 2
100
V11
I 41
V10
v 1>
v <I
V7
94
V8
N= 2 114
N
V6-- 60
_.V5 420 N= 2
v V4-- 17
major road Grade 0%
> 42nd'ave s
V9
minor road 11
s130th st
Grade 0 %
STOP xx
YIELD
Date of 'Counts:201D
Time Period:4/6pm
Prevailing Speed:35
PHF:90
Population: 250000
IOLUME ADJUSTMENTS
;Movement no. 1 11213141516171819110111112 1
7olume (vph)
1 521 1331 401 171 4201 60.1 941 1141 111 411 1001 191
Vol(pcph),Tab.10.11 571XXXXIXXXX1 191XXXXIXXXX1 1031 1251 121 451 1101 211
VOLUMES IN PCPH
57 --Vi
-- V2
--V3
v
21
V12
110
V11
I 45
V10
v 1>
<1
V7
103
A
V8
125
V9
12
V6-- ==
V5-- ==
v V4-- 19
4
OCATION:42nd ave s and e„,,Oth st
STEP 1 : RT From Minor Street 1 /-> V9
NAME:42n( Lve s
<-/ V12
2onflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
?otential Capacity,Cp(Fig10.3)
g of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
1/2 V3+V2=Vc9
20+ 133= 153 vph
5 (secs.)
Cp9 = 1000 pcph
(V9/Cp9)x100= 1.2%
P9= .99
Cm9=Cp9= 1000 pcph
1/2 V6+V5=Vc12
30+ 420= 450 vph
5 (secs.)
Cp12 = 755 pcph
(V12/Cp12)x100= 2.8%
P12= .98
Cm12=Cp12= 755 pcph
-------------------------------------------------------------------------------
STEP 2 : LT From Major Street 1 v-- V4 1 --^ V1
-- ---------------------------------------------------------
Conflicting Flows, Vc
Critical Gap, Tc (Tab.10.2)
.Potential Capacity,Cp(Fig10.3)
i of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
V3+V2=Vc4
40+ 133= 173 vph
4.5 (secs.)
Cp4 = 1000 pcph
(V4/Cp4)x100= 1.9%
P4= .99
Cm4=Cp4= 1000 pcph
V64-V5=Vcl
60+420= 480 vph
4.5 (secs.)
Cpl = 828 pcph
(V1/Cp1)x100= 6.9%
P1= .96
Cm1=Cp1= 828 pcph
•STEP 3 : TH From Minor Street 1
Conflicting Flows, Vc
-Critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
% of Cp utilized
Impedance Factor, P (Fig.10.5)
Actual Capacity, Cm
^ V8
v V11
.5V3+V2+V1+V6+V5+V4=Vc8
20+ 133+ 52+ 60+
420+ 17= 702 vph
5.5 (secs.)
Cp8 = 484 pcph
(V8/Cp8)x100= 25.8%
P8= .81
Cm8=Cp8xPlxP4
460= 484x.96x.99pcph
.5V6+V5+V4+V3+V2+VI=Vc1:
30+ 420+ 17+ 40+
133+ 52= 692 vph
5.5 (secs.)
Cpll = 490 pcph
(V11/Cn11)x100= 22.4%
P11= .84
Cm11=Cp11xPlxP4
466= 490x.96x.99pcph
STEP 4 : LT From Minor Street
<-\ V7
\-> V10
'Conflicting Flows, Vc
:Critical Gap, Tc (Tab.10.2)
Potential Capacity,Cp(Fig10.3)
Actual Capacity, Cm
Vc8(step3)+V11+V12=Vc7
702+ 100+ 19= 821vph
6 (secs.)
Cp7 = 351 pcph
Cm7=Cp7xP1xP4xP11xP12
= 351x.96x.99x.84x.98
= 275 pcph
Vc11(step3)+V8+V9=Vc1C
692+ 114+ 11= 817vph
6 (secs.)
Cp10 = 352 pcph
Cm10=Cp1OxP4xPlxP8xP9
= 352x.99x.96x.81x.99
= 268 pcph
.00ATION:42nd ave s and s130th st
NAME:42nd ave s
SHARED LANE CAPACITY
APPROACH MOVEMENTS 7,8,9
CR CR LOS LOS
AOVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) (CSH -V) CM CSH
:7 103 275 172 D
8 125 460 483 335 346 B B
9 12 1000 483 988 346 A B
•
• APPROACH MOVEMENTS 10,11,12 ---
CR CR LOS LOS
MOVEMENT V(PCPH) CM(PCPH) CSH(PCPH) (CM -V) _ (CSH -V) CM CSH
10 45 268 223. C
11 110 466 496 356 365 B B
12 21 755 496 _ 734 365 ' A B
MAJOR STREET LEFT TURNS 1,4
MOVEMENT V(PCPH) CM(PCPH) CR(CM -V) LOS
1
4
COMMENTS:
year 2011
57 828
19 1000
771
981
A
A
APPENDIX C
f'
X
•
TEXT. FROM
GEOTECHNICAL .. ENGINEERING
REPORT
1.0 SUMMARY
TABLE OF CONTENTS
W -7670
2.0 PROJECT DESCRIPTION
Page
1
3.0 SUBSURFACE EXPLORATION PROGRAM
3
4.0 SITE CONDITIONS 4
4.1 Surface Conditions 4
4.2 Subsurface Conditions 5
4.3 Groundwater 6
5.0 CONCLUSIONS AND RECOMMENDATIONS 6
5.1 Site and Subgrade Preparation 7
5.2 Structural Fill and Subbase 9
5.3 Embankment Construction 10
5.4 Temporary and Permanent Slopes 11
5.5 Retaining Structures 12
5.5.1 Rockeries 13
5.5.2 Geotextile Reinforced Earth Walls With Structural Facing 13
5.5.3 Conventional Retaining Structures 14
5.6 CBR Values 16
5.7 Pavement Thickness Design Recommendations 17
5.8 Pavement Overlays 18
5.9 Utilities 18
6.0 CLOSURE
Figure 1
Figures 2 -12
Appendix A
Appendix B
Appendix C
- Site Vicinity Map
- Site and Exploration Plan
- Subsurface Exploration Procedures and Logs
- Laboratory Testing Procedures and Results
- DCLU Client Assistance Memo #321
- King County Building and Land Development Rockery Standards
19
SUBSURFACE EXPLORATION AND
GEOTECHNICAL ENGINEERING REPORT
42ND AVENUE SOUTH IMPROVEMENTS
TUKWILA, WASHINGTON
1.0 SUMMARY
The proposed project construction appears feasible with respect to subsurface conditions encountered along
the existing roadway alignment. A brief summary of geotechnical considerations is presented below.
• Our subsurface exploration program consisted of advancing 25 hollow -stem auger borings along
the existing road alignment.
• Subsurface conditions disclosed in the explorations typically consisted of 2 to 6 feet of loose to
medium dense weathered till overlying dense to very dense till. The weathered till in most areas
was generally mantled by 1 to 3 feet of fill or road base coarse; however, certain areas with
deeper fills and loose /soft soil deposits were also encountered.
• In areas of Borings B-4, B -12, B -13, B -14, B -16, B -21, B -22, and B -23, fill material was found to
depths of 6 to 25 feet. The material encountered in these borings ranged from soft, wet silt to
medium dense granular fill, with some organics and debris.
• Based upon subsurface conditions encountered along the roadway alignment, acceptable
performance of the new pavement section appears feasible provided that proper subgrade
preparation and drainage control measures are implemented.
• The existing roadway was found to be surfaced with approximately 6 inches of asphaltic
concrete, including a 2 inch overlay, over 0 to 6 inches of crushed rock at the boring locations
drilled through the existing pavement. Compactness of the subgrade directly underlying the base
course was found to be variable. Based on the condition of the existing roadway, a pavement
overlay could be utilized in some areas. However, recent shoulder additions and underground
utility work within the existing roadway could result in deflection cracking of an overlay where the
underlying pavement section is not uniform or trench backfill is not adequately compacted.
• In areas where a new pavement section would be added or replace the existing pavement,
stripping depths would be typically range up to about 2 feet. However, in areas where loose or
Perfeet Engineering W -7670
17 January 1992 Page 2
soft fill soils underlie the roadway, greater stripping depths may be necessary, or other means
may be employed to provide a stable subgrade.
• We recommend a CBR Value of either 5 or 15 percent depending upon subgrade conditions
along the roadway alignment. The estimated limits of poor, fair, and good subgrade areas are
outlined subsequently in the main text of this report with corresponding subgrade preparation
recommendations.
• Embankment fill, sub -base and base material, including the upper portion of subgrade soils,
should be compacted to at least 95% as described in 1991 WSDOT standard specifications
(2 -03.3(14)C, method C).
• The new pavement section should be comprised of a minimum of 4'riches of asphaltic concrete
pavement underlain by suitable base course material. Recommended base course thicknesses
vary from 6 to 12 inches depending upon subsurface conditions and corresponding CBR values
along the roadway. Base course could consist of either Asphalt Treated Base (ATB) or crushed
rock.
• Permanent cut and fill slopes should be inclined no steeper than 2H:1V (Horizontal:Vertical) in
lieu of using a suitable slope retention system.
• In areas where a 2H:1V slope will not daylight within the existing road right -of -way or such slopes
are not feasible for other reasons, it will be necessary to use some form of slope retention
system. Rockeries may be used to protect the cut face in native soils up to 6 feet in vertical
height, or in fills up to 4 feet in vertical height. Rockeries are not recommended in areas with
poor subgrade conditions, rather, a system such as Keystone, Gabion, or Criblock walls should
be considered. For vertical cuts exceeding these height restrictions, an engineered slope
retention system will be required. Retaining wall altemates which may be considered include
reinforced earth walls with structural facing (such as Keystone), Criblock walls, Gabion walls,
cast -in -place cantilevered concrete walls, or cantilevered soldier pile walls.
This summary is presented for introductory purposes only, and should be used in conjunction with the full
text of this report. The project description, site conditions, and our detailed design recommendations are
Perfeet Engineering W -7670
17 January 1992 Page 3
presented in the text of the report. The exploration procedures and detailed exploration Togs are presented
in Appendix A. Laboratory testing procedures and results are contained in Appendix B.
2.0 PROJECT DESCRIPTION
The proposed project consists of widening 40th and 42nd Avenue South between East Marginal Way and
South 160th Street In Tukwila, Washington, as shown on the Site Vicinity Map, Figure 1. The proposed
section of roadway to be improved generally trends north /south and is approximately 10,200 feet in length.
We understand that the road will be widened to a maximum finished pavement width of 38 feet plus a 5' /-
foot wide sidewalk curb and gutter along each side. A surfacing of asphaltic pavement over crushed rock
or Asphalt Treated Base (ATB) base course is currently being considered for the new pavement section.
In areas along the alignment, embankment construction and /or retaining structures will be required where
the roadway will be widened. At this time, it is our understanding that the finished project will be limited to
the existing 25 to 45 foot right -of -ways; however, construction will likely extend beyond these limits and
construction easements will be required. Also, the existing roadway crosses at least five drainage courses
which are currently directed through culverts. Due to the planned roadway expansion, it may be necessary
to redesign these existing drainage crossings. The section of 40th /42nd Avenue South to be widened and
the approximate locations of the explorations advance for this study are shown on the Site and Exploration
Plan, Figures 2 through 12.
The purpose of this study was to identify general surface and subsurface conditions at the site from which
conclusions and recommendations for subgrade preparation, pavement design, earth retention structures,
and construction for the project could be formulated. The scope of work consisted of field explorations,
geotechnical engineering analyses, laboratory analyses, and report preparation. In the event that any
changes in the nature, design, or location of the new road alignment or associated structures are planned,
the conclusions and recommendations contained in this report should be reviewed and modified if
necessary, to reflect those changes. This report has been prepared for the exclusive use of Perteet
Engineering, the City of Tukwila, and their agents for specific application to this project in accordance with
generally accepted geotechnical engineering practices.
3.0 SUBSURFACE EXPLORATION PROGRAM
The field exploration program performed between 3 October 1991 and 7 October 1991 consisted of
advancing 25 hollow -stem auger borings to depths between 6 and 29 feet below the existing road grade.
The explorations were accomplished using a truck mounted drill rig supplied by a local drilling company
Perfeet Engineering W -7670
17 January 1992 Page 4
under subcontract to our firm. The approximate locations of the borings are presented on the Site and
Exploration Plan, Figures 2 through 12. In addition, hand probes were performed at approximately 10 foot
intervals at the toe of the existing road embankments located between about Stations 133 +00 and 137 +00.
The borings were located, logged, and sampled by an experienced engineering geologist from RZA -AGRA.
Representative, disturbed samples were obtained using the Standard Penetration Test (SPT) procedure as
described in ASTM:D -1586. Bulk samples were obtained from the near surface soils in the borings for
purposes of CBR determinations. CBR tests were performed on three of the bulk samples collected.
Laboratory testing also consisted of performing moisture content determinations and grain size distributions
on numerous samples collected. Refer to the boring logs in Appendix A for a description of the subsurface
soil stratigraphy encountered at the boring locations and refer to Appendix B for a summary of the
laboratory test results. The boring logs also show depths at which soil sampling was performed and list
laboratory testing on the samples, where performed.
4.0 SITE CONDITIONS
The site conditions for this project were evaluated on 3 through- 7 October 1991. The surface and
subsurface conditions are described below, while the exploration procedures and interpretive Togs of the
explorations are presented in Appendix A. The existing roadway alignment and the approximate boring
locations are shown on the Site and Exploration Plan, Figures 2 through 12.
4.1 Surface Conditions
The existing 40th /42nd Avenue South roadway generally consists of a two -lane paved surface. At the time
of our exploration, a pedestrian and bike path was being added to the east shoulder, between approximately
Stations 103 +00 to 153 +00 and the west shoulder between Stations 64 +00 to 103 +00. A majority of the
drainage along the alignment consisted of open ditch and culverts, with a few catch basins located around
intersections and driveways. Underground utilities located under the road right -of -ways included water, high
and low pressure gas, telephone, sanitary sewer, and occasional storm drains. There were also overhead
power lines along the alignment.
The existing roadway alignment appeared to generally follow the natural ground topography for most of the
project. Based on our observations and drilling results, previously placed fills on the order of 5 to 25 feet
were noticed between, but not limited to, approximately Stations 69 +00 to 71 +00, 77 +00 to 79 +00, 81 +00
to 83 +00, 134 +00 to 138 +00, and 144 +00 to 145 +00. The deeper fills typically existed in areas where the
Perfeet Engineering W -7670
17 January 1992 Page 5
roadway extended beyond natural embankment slopes, and where the roadway was constructed over
natural drainage courses. It also appeared that the road had been cut into the surrounding slopes between
about Stations 71+00 to 73 +00, 85 +00 to 87 +00, 125 +00 to 134 +00, and 148 +00 to 150 +00. Some of
these cuts and fills have been supported through the use of rockeries and retaining structures. Also, the
roadway was observed to cross five culvert crossings at approximately Stations 70 +00, 101 +50, 134 +50,
'- 142 +00, and 144 +50.
The existing pavement appeared to be in generally good condition for most of the alignment. However,
there were several sections of the roadway where severe alligator cracking, depressions, rutting, and other
distress in the asphalt were noticed. For the most part, this deterioration of the existing pavement was noted
• on the shoulder side wheel path of each lane. There were also areas around catch basins, manholes, and
over what appeared to be buried underground utilities where the pavement was severely distressed. These
areas where pavement break -up and cracking were visible include, but are not limited to, approximately
Stations 53 +50, 64 +00, 65 +50, 71+0, 72 +25, 73 +75 to 75 +25, 76 +00 to 79 +00, 80 +00 to 83 +00, 84 +75,
86 +25 to 87 +50, 92 +40 to 93 +00, 95 +50, 97 +00 to t00 +50, 101+50 to 102 +25, 103 +75 to 105 +00,
106 +00 to 112 +25, 121 +50, 122 +00, 125 +00 to 125 +50, 136 +00 to 137 +25, and 139 +25 to 140 +50.
These areas are shown on Figure 2 through 12, the Site and Exploration Plans.
4.2 Subsurface Conditions
The subsurface conditions for the subject roadway were evaluated through the program outlined in the
Subsurface Exploration Program section of this report. Subsurface conditions encountered along the
roadway appear to be quite variable based upon soils identified in our borings. Variations of soil conditions
should be expected between borings. In the event of significant variations, it may be necessary to revise
the recommendations in this report.
Borings advanced through the existing road generally encountered 4 to 6 inches of asphaltic concrete
surfacing overlying 0 to 6 inches of crushed rock base course. The subgrade directly beneath the base
course was found to be variable with respect to both composition and compactness. Borings located within
the road shoulder typically encountered 4 to 6 inches of crushed rock or gravel surfacing. Both the
pavement and shoulder sections generally mantled weathered native soils overlying dense unweathered
native soils. However, man - placed fill was found underlying the pavement section between, but not limited
to, approximately Stations 68 +00 to 74 +00 (B4), 100 +00 to 112 +50 (B12 to B -13), 115 +50 to 118 +50
(B -16), 130 +00 to 137 +50 (B -21 to B -23), and 144 +00 to 146 +00 (B -25). Underlying the fill material,
Perfeet Engineering W -7670
17 January 1992 Page 6
medium dense /stiff to very dense /hard glacial till soils were encountered In all the explorations to the full
depths drilled, except in Borings B -21 and B -22 where zones of soft and medium stiff silt were found
between the overlying fills and deeper unweathered soils. These soils are Interpreted to be of glacial origin
due to their high density, consistency and grain size distribution. The glacial till and all soil units
stratigraphically below the till have been overridden and compressed by the weight of a past glacial ice
mass.
As previously stated, significant amounts of fill were encountered in Borings B-4, B -12 through B -14, B -16,
B -21 through B -23, and B -25. In the areas where these borings were drilled, it was obvious that the roadway
grade had been raised to cross existing drainage courses. In the case of Borings B-4, B -21 through B -23,
and B -25, water was observed flowing through existing culverts at the bottom of the respective drainage
course. Fill thicknesses encountered ranged between 8 to 20 feet over the culverts, and 2 to 10 feet where
the fill was placed as part of a cut /fill operation.
Hand probing performed near the bottom of the high road embankments between about stations 133 +00
and 137+00 revealed generally firm soils below a surficial thickness of 2 to 6 inches of topsoil and soft soils.
4.3 Groundwater
Groundwater was encountered in 3 of the 25 borings. Groundwater depths at the time of our exploration
were about 61/2 feet in B -24 and 19 feet in B -21 and B -22. It should be noted that some orange mottling
was observed in some of the borings along the alignment. This mottling is interpreted to be indicative of
prior fluctuation of groundwater levels. Because of the relatively impermeable nature of the unweathered
glacial till soils, the seepage was interpreted to be a'perched" groundwater condition above the weathered
till /fill - glacial till contact. Perched groundwater levels should be expected to fluctuate with variations in
precipitation and temperature, drainage conditions, local land use, and other factors. Localized zones of
perched water near the weathered till /fill- glacial till interface should be anticipated, particularly if construction
is performed during the wet winter months.
5.0 CONCLUSIONS AND RECOMMENDATIONS
Based on the subsurface conditions encountered at the site, the proposed road improvement project
appears feasible from a geotechnical standpoint. Proper subgrade preparation and drainage will be critical
for acceptable performance of pavement sections over the desired project design life. A design life of 10
Perfeet Engineering
17 January 1992 Page 7
W -7670
years Is typical for a roadway pavement. A thin overlay Is generally required at the end of the design period
in order to bring the paved surface back to a near -new condition.
As previously discussed, the existing roadway was found to be surfaced with approximately 4 to 6 inches
of asphaltic concrete overlying 0 to 6 inches of crushed rock, mantling weathered till or fill soils. While most
of the roadway pavement was found to be in relatively good shape, there were several sections (discussed
in the Surface Conditions section of this report) where the pavement condition was observed to be generally
poor to fair. It is our understanding that existing road surface elevations may be modified somewhat. Road
profiles furnished us indicate that some minor regrading is planned which will require cuts and fills ranging
up to about 2 feet within the existing roadway and up to about 14 feet at the edges of the right -of -ways, to
accommodate the planned improvements. It is recommended that all cuts and embankment fills be
adequately sloped or supported with a suitable retaining structure, rockeries may be used where
appropriate. New embankment fills should be properly keyed and benched into existing slopes.
As previously discussed, shallow hand probing was performed at the base of the embankments between
about stations 133 +00 and 137 +00. although the hand probes did not reveal evidence of any obviously
soft surficial deposits, we recommend that a limited number of borings be drilled as outlined in our proposal
letter of 8 May 1991 for purposes of more accurately defining subsurface conditions in these areas. The
need for special embankment subgrade preparation and construction measures and estimated magnitude
and duration of embankment settlement can be addressed at that time.
If it is desired to save and overlay existing pavements which are presently in good condition, it should be
realized that these areas will likely require more frequent maintenance and repair than the new pavement
areas. We suggest that the initial benefits of saving existing pavements be weighed against the potential
for some added maintenance and repair over the project design life. We have indicated which sections of
the alignment would be suitable for overlay in Section 5.8 of this report.
5.1 Site and Subgrade Preparation
Site stripping for the placement of new structural fill or embankment fill should consist of removing existing
vegetation, topsoil, organic rich soils, unsuitable fills, and existing roadway pavements, where required. In
areas where pavement degradation or poor to fair subgrade conditions exist, we recommend that the
existing pavement be removed and the subgrade rehabilitated. Following the removal of existing pavement,
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the subgrade should be cleared of any, accumulation of organics, debris, pavement remains, or other
deleterious material, and prepared as outlined below.
Poor subgrade conditions were encountered in Borings B-4 and B -14. We have roughly estimated that areas
between about Stations 68 +00 and 72 +00 (near B-4) and Stations 108 +00 and 112 +00 (near B -14) may .
have poor subgrade conditions based on a crude interpolation between borings. Since borings were spaced
on the order of 400 feet apart, the actual extent of poor subgrade conditions should be verified at the time
of construction and the interpolated stationings presented in this report should be used for design purposes.
Loose /soft fill soils extended to a depth of about 16 feet in B-4 and 7 feet in B -14. In order to provide a
stable subgrade for pavements, the unsuitable deposits would have to be overexcavated down to firm native
soils. Where depths of such deposits are great, complete overexcavation would likely be difficult and costly;
therefore, we are of the opinion that overexcavation may be limited to 2 feet provided that a suitable
geotextile reinforcement fabric is placed above the stripped subgrade after thorough proofrolling, and a
minimum thickness of 2 feet of compacted Import sand and gravel subbase is placed above the fabric.
Additional overexcavation will be required to remove any organic -rich materials exposed upon the initial 2
feet of stripping; however, we anticipate that this would only be required in localized areas.
Fair subgrade conditions were encountered in Borings B -1, B -7, and B -10. We have roughly estimated that
areas between about Stations 50 +50 and 56 +00 (near B -1), Stations 80 +00 and 84 +00 (near 8 -7), and
Stations 92 +00 and 97 +00 (near B -10) may have fair subgrade conditions. Loose fill soils extended down
to depths of about 7 feet in 13-1, 6 feet in B -7, and 3 feet in B -10. In order to provide a stable subgrade for
pavements, we recommend that the upper 2 feet of the existing subgrade be overexcavated and replaced
with compacted import sand and gravel subbase. The stripped subgrade should be thoroughly proofrolled
and any obvious unsuitable materials excavated prior to placement of the subbase. Based upon the
composition of the near surface soils encountered at these locations, It does not appear that geotextile
reinforcement fabric will be necessary; however, there may be localized areas where such measures would
be desirable if poorer quality existing fill is encountered.
Subgrade conditions in the borings over the remainder of the alignment were found to be relatively good
and stripping depths beyond removal of surficial vegetation, topsoil, or existing pavements are anticipated
to be minimal for a majority of these areas. Localized zones with unsuitable fill, organic -rich soils or other
deleterious materials may occur between these boring locations, however, and such materials should be
overexcavated as necessary. After stripping of all unsuitable materials, the subgrade soils exposed should
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be proofrolled with a large drum vibratory roller or other suitable equipment to obtain a firm and unyielding
ground surface. Any obvious soft or spongy areas should be excavated and replaced with properly
compacted structural fill. The upper two feet of subgrade material beneath pavement sections should be
compacted to at least 95 percent of ASTM:D -1557 maximum dry density, or In general accordance with
WSDOT /APWA Standard Specification 2-06, ' Subgrade Preparation', of the 1991 WSDOT Standard
Specification for Road, Bridge, and Municipal Construction.
Prior to exposing the existing subgrade soils, any surface or groundwater should be collected and routed —
away to a suitable drainage facility to facilitate earthwork construction. At this time, we do not anticipate
the need for french drains at any speck location. However, the need for such measures should be
evaluated during construction based on the capability of other planned and existing drainage devices to
protect the pavement from excessive moisture infiltration.
The need for, or advisability of proofrolling during wet weather periods should be evaluated at the time of
construction due to the moisture sensitive nature of the site soils. Disturbance to soils with more than about
5 percent fines (that portion of material which passes the U.S. No. 200 sieve based on that fraction passing
the U.S. No. 4 sieve) would reduce silty soils to mud. We recommend that a representative from RZA -AGRA
observe soil .conditions prior to and during proofrolling to evaluate the suitability of stripped subgrade soils
prior to further construction.
In areas where distressed pavement is due to excessive settlement of existing utility trench backfill, we
recommend that the existing cracked pavement be removed, and the backfill materials be overexcavated
to a minimum 2 feet below the bottom of pavement. Where local small excavations are required, it may
expedient to use select import soils rather than the silty on -site soils or fills, especially in wet weather or
adverse site conditions. We recommend that any fill placed in these excavations be placed in accordance
with the structural fill procedures outlined in the following section of this report.
5.2 Structural Fill and Subbase
Structural fill and subbase materials should consist of clean, free draining, well graded sand and gravel
(3 -inch minus). Alternately, structural fill /subbase could consist of Gravel Base or Gravel Borrow meeting
the requirements' of 1991 WSDOT Standard Specifications 9 -03.10 and 9 -03.14, respectively, with
modification to allow for a maximum of 5 percent (by weight) passing a U.S. No. 200 Sieve based on that
portion passing a U.S. No. 4 Sieve. The upper 2 feet of structural fill beneath paving should be compacted
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to at least 95 percent of the modified Proctor (ASTM:D -1557) maximum dry density. Altemately, structural
fill for road subgrades could be placed in accordance with WSDOT Standard 2 -03.3(14)0, Compacting Earth
Embankments, Method C, from the 1991 WSDOT Standard Specification for Road, Bridge and Municipal
Construction. The suitability of various soils for placement and compaction as structural fill depends
primarily upon the fines content (that soil fraction finer than the U.S. No. 200 sieve) and the moisture content
of the soil at the time of placement. Generally, as the amount of fines increases, adequate soil compaction
becomes more difficult or impossible to achieve. Soils containing more than about 5 percent fines, such
as most of the site soils, cannot be consistently compacted to a firm, non- yielding condition when the
moisture content is more than about 2 percentage points above optimum.
In the event that site soils cannot be used as structural fill, we recommend that clean, granular import
material be utilized. Clean fill should be considered as free - draining sand and gravel containing less than
5 percent passing the U.S. No. 200 sieve (by weight) based on that soil fraction passing the U.S. No. 4
sieve. Such material can generally be effectively compacted throughout a wider range of site and weather
conditions. Materials specified in 1991 WSDOT /APWA Standard Specifications for Road, Bridge, and
Municipal Construction, Section 9 -03.10, "Aggregate for Gravel Base ", or 9 -03.9(1), "Ballast", may be utilized
for this purpose, except that the maximum percent passing the U.S. No. 200 sieve should be modified as
described above.
We recommend that embankment and utility backfill be placed and compacted in accordance with WSDOT
1991 Standard Specifications for 'Compacting Earth Embankments ", Method C, specification 2 -03.3(14).
We recommend that the fill placement be monitored by a qualified geotechnical engineer to evaluate whether
soils excavated would be suitable for use as structural fill at their natural moisture contents and to confirm
that adequate compaction has been achieved.
5.3 Embankment Construction
We recommend that all fill placed on slopes or with a sloping finished grade be compacted according to
the structural fill recommendations previously discussed within this report. Permanent fill placed on slopes
steeper than 5H:1V (Horizontal:Vertical) should be keyed and benched into soils of the underlying slope in
general accordance with WSDOT /APWA specification 2.03.3(14), 'Embankment Construction ", as found in
the 1991 WSDOT Standard Specifications for Road, Bridge, and Municipal Construction. In conformance
with this specification, we recommend a downslope key be cut into the undisturbed native soil. Terraces
•a 1
•
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should be cut at least 5 feet into the slope and should not exceed 5 feet in height. The exposed soils at the
bottom of the key should be compacted to a minimum of 90 percent density according to ASTM:D -1557
prior to the placement of structural fill. Fill placement should proceed in horizontal lifts from the bottom of
the slope to the top. The body of the fill should be compacted to the same density as the exposed native
soils. As each bench is constructed, the fill should be compacted to a minimum of 90 percent compaction
as determined by ASTM:D -1557. In areas where the slope is flatter than 5H:1V, we also recommend that
the structural fill be compacted to a minimum of 90 percent compaction as determined by ASTM:D -1557.
Subgrade preparation and filling should all be performed under the full time observation and testing of a
representative from our firm. In this way the adequacy of the work may be evaluated as it is performed and
if any questions arise, they may be resolved promptly.
Finished fill slopes should not be steeper than 2H:1 V. To help control erosion, we recommend that the
exposed soils be seeded or thoroughly landscaped with vegetation. A manufactured erosion control product
such as a jute matting or Excelsior Mat should be considered to protect the slope while the vegetation
becomes established, depending on the time of year planting occurs. If necessary, an impervious cover
should be placed over exposed slope faces, particularly to protect temporary slopes during construction
while vegetation is stripped.
Surface water runoff should be diverted away from all cut and fill slopes during construction and on a
permanent basis. The use of berms and swales should be considered for this purpose. Based upon current
plans, it does not appear that embankment slopes will be of sufficient height to warrant terracing.
5.4 Temporary and Permanent Slopes
Temporary excavation slope stability is a function of many factors including the following:
1. The presence of groundwater
2. The type and density of various site soils
3. The depth of cut
4. Surcharge loading adjacent to the excavation
5. The length of time the excavation remains open
It is exceedingly difficult under these variable circumstances to pre - establish a safe and maintenance free
temporary cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe slope
configurations since the contractor is continuously at the job site, able to observe the nature and condition
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of the cut slopes, and to monitor the subsurface materials and groundwater conditions encountered. It may
be necessary to drape temporary slopes with plastic or other means to protect the slopes from adverse
weather conditions and minimize sloughing and erosion. All excavations should be adequately sloped or
supported to prevent injury to personnel from local sloughing. All excavations should be constructed to
conform with applicable State, Federal, and local regulations (OSHA, WISHA, etc.).
Based upon subsurface conditions encountered along the existing roadway, it appears that temporary cuts
into native soils will be feasible at an average 1 H:1 V inclination. Temporary safe slope inclinations should
be determined during construction by the contractor based on actual soil and groundwater conditions
encountered. Slopes of 3/4H :1V and 1.5H:1V should be acceptable for temporary cuts in glacial till and
loose fill, respectively.
We recommend that all permanent slopes be designed at a 2H:1V inclination or flatter. As described
previously, groundwater seepage should be intercepted and diverted. To reduce the risk of surficial erosion,
permanent slopes should be revegetated or otherwise protected as soon as possible following construction.
If seepage zones are present on a cut slope, the use of a rock facing should help reduce piping and erosion
problems.
The face of compacted fill slopes should be compacted to the same 95 percent density as the body of the .
fill. This may be accomplished by overbuilding the embankment and cutting back to the planned finished
surface. Alternatively, the surface of the slope may be compacted as it is built or upon completion of the
fill placement.
5.5 Retaining Structures
We understand that the necessary space may not be available to adequately slope back cut and fill
embankments within the existing street right -of -way. Therefore, cut and fill embankments would have to be
constructed near vertical to stay within these boundaries. We understand that rockeries and geotextiie
reinforced earth walls with keystone facing are currently being considered for this purpose. Based upon
subsurface conditions encountered, we recommend that rockeries be used for near vertical cuts faces up
to 6 feet in height, while reinforced earth walls with structural facing (or equivalent) appear feasible for cuts
of greater vertical height. It should be noted that rockeries are not engineered retaining structures, and
function only to face otherwise stable slopes and protect them from sloughing and erosion. Rockeries
should be limited to 4 feet in height in fill areas, and should not be used in "poor subgrade areas as listed
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previously in this report. Rather, an engineered retention system should be used in 'poor subgrade areas,
of which, Gabion, Keystone, or Criblock walls may be some of the most practical and economical.
5.5.1 Rockeries
A rockery wall can be used to protect the cut face of an otherwise stable, natural or fill slope if periodic
maintenance can be tolerated. Maintenance may be required to replace fallen or loosened rocks, and to
repair any settlement or washouts behind the rockery. The use of rockeries does increase the risk of
long -term settlement or soil washout of the retained soils. Rockeries should be constructed in general
accordance with the requirements of the regulatory agency having jurisdiction over the project. Should such
guidelines not be available, the City of Seattle Department of Construction and Land Use (DCLU) Client
Assistance Memo #321 or the King County Building and Land Development Rockery Standards should be
referred to as a guideline for rockery construction. We recommend rockeries be constructed of sound,
durable rock with a battered face no steeper than 6H:1V. The bottom course of each rockery should be
founded in at least medium dense native or fill soils. The rockery should also be backed by a drainage
envelope and perforated drain tile. An example of such a drainage system is outlined in the King County
Rockery Standards as well as DCLU Memo #321. We have provided copies .of the DCLU Memo and King
County Rockery Standards in Appendix C of this report for yourreference.
Since rockeries are not retaining structures, they are not generally used to face unreinforced fill. However,
in our opinion, if structural fill and embankment fill are placed in accordance with the recommendations
previously discussed in this report, a rockery could be used to face fill slopes up to 4 feet in vertical height.
The bottom course of a rockery facing fill would need to be founded in at least medium dense to dense
native or fill soils. If such bearing soils are not present, it would be necessary to use an engineered
retention system. A proprietary wall system such as *Gabion, Keystone, or Criblock walls may be some of
the most practical and economical given their tolerance for small amounts of post - construction settlement
and the fact that standard manufacturer's designs are available for such low walls. We recommend that low
walls in such areas be placed above at least 2 feet of structural fill compacted to 95 percent of the modified
Proctor maximum dry density.
5.5.2 Geotextile Reinforced Earth Walls With Structural Facing
To retain cuts in fills beyond the height limitation of rockeries, a geotextile reinforced earth wall with a
structural facing could be utilized. Wall facings which are compatible with geotextile reinforced earth walls
include Keystone walls, gabions treated landscape timbers, and railroad ties. Such a system would require
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that the facing be supported on a 6 inch layer of drainage aggregate, and that drainage be provided behind
the facing. Drainage should consist of 4 inch perforated PVC pipe or drain tile at the base of the wall
surrounded by at least 6 inches of drainage aggregate. The backfill within 12 inches behind the wall facing
and more than 12 inches below the surface of retained soils should consist of the same drainage aggregate
that is to be placed around the drain pipe. The drainage aggregate should consist of pea - gravel or washed
rock, and should be separated from the native soils by means of a suitable filter fabric. Alternatively, the
drainage aggregate could meet the requirement of 1991 WSDOT Standard Specification 9 -03.13 or
9-03.12(2).
For preliminary design purposes, reinforced earth walls may be designed for a maximum soil bearing
pressure of 2,500 pounds per square foot (psf), provided that the wall is founded above at least medium
dense undisturbed native or fill material. Reinforcement length of the fill behind the wall face is typically
equal to 70 percent of the embankment height, or 4 feet, whichever is greater. Reinforcement is typically
installed in continuous sheets at a vertical spacing of about 18 inches. The sheets should be overlapped
3 feet at the top of each layer. An angle of internal friction of 35 degrees and a unit weight of 125 pounds
per cubic foot may be used for granular backfill soils compacted to 95 percent of modified Proctor maximum
dry density as outlined in ASTM:D -1557, for purposes of final design of geotextile reinforced walls.
The facing should be constructed simultaneously with the reinforced earth wall, with the geosynthetic
reinforcement tied into the facing at regular intervals. The facing must either allow the geosynthetic to
deform freely during construction without any buildup of stress on the face, or the facing connection must
be designed to take the stress. Finished grades should be sloped to direct water away from the wall face.
The manufacturer or vendor of the patented reinforced earth wall system selected should be consulted to
provide detailed wall design recommendations. We would be available to furnish any necessary soil data
and assist the party performing the wall design.
5.5.3 Conventional Retaining Structures
As an alternative to reinforced earth walls, conventional retaining wall systems such as cast -in -place
cantilevered concrete, Criblock, Gabion, Keystone, or cantilevered soldier pile walls could be utilized to retain
slopes. Retaining wall foundations should have a minimum embedment depth of 2 feet and should be set
back at least 5 feet horizontally from the face of slopes. Walls conforming to this criteria may be designed
for a maximum allowable soil bearing pressure of 2,500 psf. We recommend an allowable base friction value
of .35, utilizing a factor of safety of 1.5, for retaining walls constructed upon medium dense to dense native
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soils or properly compacted structural fill. Allowable active pressure values can be designed for an
equivalent fluid unit weight of 35 pcf and 55 pcf for level backfill and backfill sloping at 2H:1V behind the
wall, respectively. Allowable passive pressures values for planned walls should be designed for an
equivalent fluid unit weight of 300 pcf for level ground or 150 pcf for 2H:1V sloping ground in front of the
wall. These values are also calculated utilizing a factor of safety of 1.5. Lateral passive soil resistance
against the faces of retaining walls may be utilized below a depth of 3 feet on slopes, or below 1 foot in
cases where the slope in front of the wall is flatter than 5H:1V. The allowable soil bearing pressure and
friction coefficient may be increased by one -third when considering seismic forces.
The practicality of using any of the wall types mentioned above will depend upon the actual wall height,
construction, space and access constraints, economic considerations, and whether slopes are in cut or fill
areas. Slopes may be retained by either one single system or a combination of retaining wall systems. A
brief description of the various retaining wall systems is given below:
Cantilevered Reinforced Concrete Walls
These walls are constructed of cast -in -place reinforced concrete and consist of two components;
a base footing and a vertical stem' wall. These walls can be designed for heights up to
approximately 35 feet. It is preferable that these walls be cast above a firm subgrade to limit
differential settlement, as these walls are sensitive to such settlements. Based upon our preliminary
findings, the soil conditions appear suitable for construction of such a wall system. However,
extensive temporary cuts would be required to provide access to the footing locations.
Gabion Walls
Gabion walls act as a gravity wall and consist of wire baskets laced together and filled with rock.
These walls are flexible and can accommodate some post - construction differential settlement.
Gabion walls have been used successfully for similar applications with wall heights In excess of 30
feet. Gabions are relatively labor intensive; however, overall costs are generally considerably lower
than conventional cast -in -place concrete walls. Similar to other gravity walls, gabions require
temporary cuts to provide access to the wall base location.
Criblock Walls
Criblock walls are comprised of precast reinforced concrete "dogbone" shaped members which are
stacked in an interlocking manner. The resulting cells are backfilled with either soil or crushed
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rock /gravel as wall construction progresses, resulting in a gravity wall -type structure. The wall face
may be vegetated if the cells are backfilled with soil. Criblock walls are also somewhat tolerable to
post - construction differential settlement; however, not to the same degree as Gabions. Criblock
walls are labor intensive and require careful subgrade preparation to create a level starting base.
Criblock walls are also generally less expensive than conventional concrete walls and can be
constructed up to heights of about 30 feet or greater provided sufficient soil bearing is available.
Temporary cuts would be required for this alternate.
Keystone Walls
Keystone walls are constructed of concrete modules interlocked with reinforced fiberglass pins.
Standard size Keystone units can be used to construct gravity-types retaining walls up to about 6
feet high provided no surcharge exists behind the wall. Keystone used in conjunction with
geotextile reinforced earth can be used to construct walls of greater height.
Cantilevered Soldier Pile Walls
These walls consist of regularly spaced vertical steel soldier piles which are the main members used
to resist lateral forces. These walls can be designed to retain cuts of up to about 15 feet high
without lateral bracing members such as tieback anchors. Treated timber lagging is placed between
the vertical soldier pile members to prevent soil sloughing and erosion. A panel or shotcrete facing
can be used for aesthetic appeal. Soldier pile walls are generally costly when compared to other
retaining wall systems, particularly proprietary walls. The greatest advantages of these walls are that
they are preinstalled prior to slope excavation which entails less risk, and that they cause minimal
disturbance to the soil behind the wall and any structures supported on these soils.
5.6 CBR Values
The paving subgrade must be adequately prepared as recommended in Section 5.1 prior to placement of
subbase, base course /Asphalt Treated Base (ATB), and asphaltic paving sections. Three CBR (California
Bearing Ratio) tests were performed on bulk samples obtained during drilling. The near surface soils
encountered at these locations consisted of either fill or weathered till comprised of variable amounts of
sand, silt and gravel. Due to the variability of the upper site soils and based on our experience with similar
projects in the vicinity, we have determined that a CBR value of 15 percent may be used for pavement
thickness design for areas with good subgrade conditions as described in Section 5.1. A CBR value of 5
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percent may be used for the areas with poor and fair subgrade conditions described In Section 5.1 provided
that the subgrade is prepared in accordance with the recommendations contained In that section.
5.7 Pavement Thickness Design Recommendations
Provided new subgrades are prepared in accordance with this report, and utilizing the CBR values of Section
5.6, the pavement sections given below be used. These design recommendations have been calculated in
accordance with WSDOT Asphalt Pavement Design Methodology and traffic volumes provided to us by
Perteet Engineering. Following the recommendations contained therein, and assuming roads are founded
upon a subgrade of either undisturbed medium dense to dense native soils or properly compacted structural
fill subbase, pavement sections may be designed as follows:
1. Areas with Recommended Subgrade CBR of 5%
• 4 inches Asphaltic Paving Surfacing
• 12 inches Crushed Aggregate Base Course
• 24 inches 95% Compacted Subbase (underlain by geotextile reinforcement fabric in 'poor"
subgrade areas)
2. Areas with Recommended Subgrade CBR of 15%
• 4 inches Asphaltic Paving Surfacing
• 6 inches Crushed Aggregate Base Course
• 12 inches 95% Compacted Subgrade
The following substitution relationships may be used if it is desired to modify the above recommended
pavement sections. We recommend that the asphalt surfacing thickness be limited to a minimum of 4
inches, and that the asphalt paving mix be selected considering the type and volume of traffic use.
1 inch asphalt = 2 inches of crushed rock
1 inch Class B asphalt = 1.25 inches Asphalt Treated Base (ATB)
1 Inch ATB = 1.6 Inches crushed rock
The road surface should be constructed with a crown to prevent water from ponding on the road surface.
Base course and ATB should meet the specifications defined in the 1991 WSDOT Standard Specifications
for Road, Bridge, and Municipal Construction, Section 9 -03.10, 'Crushed Surfacing', and Section 9 -03.9(3),
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'Aggregate for Asphalt Treated Base (ATE)". The base course should be compacted to at least 95 percent
of the modified Proctor maximum dry density.
5.8 Pavement Overlays
Pavement overlays may be utilized along portions of the alignment. Based upon the results of our field
explorations and site reconnaissance, we are of the opinion that the sections of road between about Stations
56 +00 to 68 +00, 83 +00 to 92 +00, 112 +00 to 136 +00, and Station 141 +00 to 153 +00 are intact pavement
suitable for overlays. In areas where overlays are to be used, the total pavement section, with overlay,
should be at least equivalent to the recommended new pavement section for the specific area. Although
computed asphalt and base course thicknesses may be less or equal to those already existing in many
areas, consideration must be given to the fact that subgrade conditions In those areas were found to be
variable and would likely not be as good as new pavement subgrades in similar areas if prepared as
recommended in this report. It should be realized that overlay areas may not perform quite as well as new
pavements; however, we feel that performance will likely be acceptable provided that an overlay thickness
of no less than 2 inches is used.
5.9 Utilities
It is understood that the proposed development may include relocation of existing utilities and installation
of new utility lines. It is anticipated that either the loose to medium dense weathered till /fill or dense to very
dense glacial till would be encountered within most utility trench excavations. Groundwater was
encountered at depths of 61/2 to 19 feet in three of the borings. Saturated zones may develop within
existing fill and weathered till at the glacial till interface and in areas underlain by silty materials.
The exposed soils at the bottom of utility trenches should be overexcavated to facilitate placement of
suitable bedding material beneath utility lines, where bedding is required. All back-fill up to the finished grade
level should be mechanically compacted as recommended in Section 5.2. Pipe bedding material should
meet the requirements of 1991 WSDOT Standard Specifications for Road, Bridge and Municipal
Construction, or the regulatory agency having jurisdiction over the project, if different.
Temporary excavations to greater than 4 feet deep should not be expected to stand vertically without
shoring. Unshored excavations should be sloped back no steeper than 1.5H:1V in the fill and 1 H:1 V in the
native soils. All applicable OSHA and WISHA safety requirements should be met to protect workers.
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Utility trench backfill could utilize the on -site soils during extended dry weather periods, along portions of
the project length. Section 5.2 of this report discusses Import fill materials which would be suitable, and
compaction requirements. The use of on -site soils for utility backfill should be restricted to those soils with
less than 50 percent passing a No. 200 Sieve, at moisture contents within 2 percent of optimum, and which
can be maintained at specified moisture contents during compaction. Import subbase should be used in
the upper 2 feet of trench, below the crushed rock. Based upon our explorations, it appears that roughly
half of the borings completed encountered near- surfadesoils with less than 50% passing a 200 sieve, and
of these a substantial portion were more than 2 percent above optimum moisture. Import fill will likely be
required for substantial portions of the trench backfill.
Precautions should be taken in the compacting of backfill to avoid damage to the utility lines. Heavy
compaction equipment should be kept back at least 3 feet to minimize excessive lateral stresses on utilities.
It is suggested that the backfill along the two sides of a pipe be placed simultaneously and brought up to
at least the top of the pipe in equal lifts and level heights during the backfill operation.
6.0 CLOSURE.
The conclusions and recommendations presented in this report are based on our understanding of the
proposed project and our subsurface exploration program and geotechnical engineering evaluation. The
number, location, and depth of the borings were accomplished within the authorized scope of work and site
constraints. Since the project is in the planning stages at the time of this writing, we recommend that
RZA -AGRA be provided the opportunity to review the geotechnical aspects of project plans and
specifications in order to document that the recommendations and design considerations presented in this
report have been properly interpreted and implemented for this project.
The integrity of new pavements will depend on the proper site preparation, fill placement and construction
procedures. RZA -AGRA would be available to provide geotechnical engineering services during earthwork
phases of this project. If variations in subsurface conditions are observed at that time, RZA -AGRA would
be available to provide additional geotechnical recommendations to minimize delays as the project
proceeds.
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We appreciate the opportunity to be of service to you. Please do not hesitate to contact our office if you
have any questions or require further information after reviewing this letter report.
Respectfully submitted,
RZA -AGRA
4.4J
I(eith S. Schembs
Engineering Geologist
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Benjamin R. Wkikts,'R'.E. - .� _ • ;1
Senior Project Engniqer•
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John E. ZipF%r,
Associate
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APPENDIX D
SUMMARY OF
COMMUNITY' : INVOLVEMENT
PROGRAM
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TABLE OF CONTENTS
Summary Report 1
Focus Group Discussion: August 6, 1991'. 4
Public Workshop: August 14, 1991 9
February Mail Survey 14
Map: Location of Respondents
Map: Preferred Parking by Location of Respondent
Map: Preferred Sidewalks by Location of Respondent
Public Workshop: February 27, 1992 20
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
COMMUNITY INVOLVEMENT: SUMMARY REPORT
Background
The Tukwila 42nd Avenue South Improvement Project is a street design program to
improve traffic flow and safety on 42nd Avenue South between South 160th Street
and South 130th Street in Tukwila. The City of Tukwila obtained the consultant
services of Perteet Engineering, Inc. of Everett in June 1991 to do the design
study for the project. Carolyn Browne Associates, a Bellevue marketing research
and community involvement firm, was hired by Perteet Engineering to conduct a
community involvement program for the project which would inform the immediate
community and solicit comments and suggestions for the street design.
Summary of Concerns and Suggestions
Those who reside along 42nd Avenue South and 40th Avenue South, within the
project area boundaries, have a strong sense of identity with their residential
neighborhood. They want the area to maintain its residential character and they
have strong concerns about safety issues on the street. The improvements most
wanted include sidewalks, traffic law enforcement and design elements that will
reduce vehicle speeds, crosswalks where needed, improved drainage, better
lighting and an overall attractive appearance that will be an asset to the
community.
Community Involvement Tasks Accomplished
During the project, the City of Tukwila made every effort to contact and hear
from anyone affected by the recommended design improvements. These contacts
included: A focus group discussion with a representative group of citizens in the
project area on August 6; a brief newsletter flyer was distributed to approxi-
mately 500 homes in the project area, describing the planned project and inviting
people to attend a public workshop; an open public workshop to solicit concerns
and improvement suggestions; held at the Tukwila Community Center on August 14;
a ; a mail questionnaire distributed to every household in the immediate vicinity
of the project area and to people who had contacted the city requesting to be
notified about the project; and a second public workshop and open house to
respond to questions about the recommended improvements and seek additional
suggestions. In addition, members of the City of Tukwila Public Works staff
visited with residents in the project area who voiced particular concerns•and
attempted to identify all citizens who would be affected by the project. •
Focus Group Summary
Thirteen people residing in the immediate vicinity of the project area
participated in a discussion about the project at the Tukwila Community Center
on Augus.t 6.
They talked about their concern that the street maintain its residential
character and that the street improvements should not promote more people using
42nd Avenue South as an alternative to Highway 99.
CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
COMMUNITY INVOLVEMENT: SUMMARY REPORT - Page 2
The major issues brought up were: pedestrian safety (especially in the vicinity
of the schools); the amount of traffic, including truck traffic, currently on the
street; dangerous pedestrian areas at certain cross - streets (especially 152nd and
154th); and transitions from the street to certain properties which have steep
driveways.
The improvements mentioned most strongly include: Sidewalks or pedestrian paths,
adequate parking where needed, a retaining wall near 139th, better drainage,
crosswalks at 152nd and 154th, better traffic controls and enforcement to reduce
speeding, underground utilities, better lighting and an overall attractive
appearance.
Summary of First Public Workshop
Meeting announcements were distributed to approximately 300 homes of people
living, or owning property, on or near 40th Avenue South and 42nd Avenue South,
between East Marginal Way and South 160th Street, inviting them to attend a
public workshop at the Tukwila Community Center on August 14, 1992. Nineteen
people attended the workshop, listened to a presentation, shared responses in
small groups and completed individual questionnaires.
The major concerns identified in the group discussions were: Property restoration
and landscaping; drainage; speeding on the street; pedestrian safety; property
encroachment; maintaining the residential character of the street; and paying for
the cost of underground utilities. The improvements suggested by the groups
included: better street lighting; bicycle paths; and adequate on- street parking.
The responses tabulated from the completed questionnaires showed concerns for
drainage issues, access to property and the loss of landscaping that has served
as a screen. The improvements requested most frequently were: sidewalks; bicycle
paths; improved drainage; underground utilities; adequate on- street parking; and
better street lighting.
Summary of Tabulated Responses from Mail Survey
In early February, approximately 500 residents and property owners in the project
vicinity received a questionnaire, asking their opinion about some specific
improvements. Sixty -two residents completed and returned a questionnaire in time
to be tabulated and reported at the second public workshop on February 27.
Asked a specific question about sidewalks preference, most people said they
definitely want sidewalks, but there was no strong pattern of agreement as to
whether 'they should be on the east side or west side of the street only or on
both sides.
People were quite divided on a question about whether parking is needed. About
a fourth of those who responded said they want no more parking, another fourth
said there should be sidewalks wherever possible, and the remainder were split
as to whether parking should be allowed on the west side only, both sides or the
east side only; 10% had no opinion about parking.
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CAROLhN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
COMMUNITY INVOLVEMENT: SUMMARY REPORT - Page 3
The improvements most frequently mentioned by those completing a questionnaire
included sidewalks (especially for the safety of the school children); retaining
or providing more parking; reducing speeds and enforcing speed limits;
underground utilities; better lighting; resurfacing the street; covering the
drainage ditches; and reducing traffic.
Summary of Second Public Workshop
Over 500 residents and property owners in the vicinity of the project received
the mail questionnaire and an invitation to attend a second workshop at the
Tukwila Community Center on February 27, 1992. Thirty people attended the
meeting.
The meeting was conducted more as an open house with people perusing exhibits and
• asking members of the consultant team or the Tukwila Public Works staff questions
and sharing their thoughts and ideas.
Eleven-of those who attended had not returned a mail questionnaire, so they
completed a similar questionnaire at the meeting.
People at the workshop reiterated the themes heard previously: Maintain the
residential character of the street; provide sidewalks; provide adequate parking
only where needed; take care of drainage problems; control traffic speeds;
improve street lighting; and provide additional pedestrian safety where needed
(crosswalks, signals, stop signs, etc.).
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
FOCUS GROUP DISCUSSION: CONDUCTED AUGUST 6, 1991
Introduction
Several citizens living on 42nd Avenue South in the project area were invited to
be participants in a small group discussion to share their concerns and opinions
about the 42nd Avenue South Improvement Project. The participants were
recruited, at random, from listings in the Cole Directory. The group met at the
Tukwila Community Center on August 6, 1991, from 7 :30 - 9:00 p.m. The discussion
was facilitated by Carolyn Browne. Ross Heller, from the City of Tukwila, was
an observer and was introduced to the participants at the end of the discussion.
The group included six men and seven women, ranging in age from late 20's to late
60's. They have resided in the Tukwila area anywhere from a few months to more
than 30 years.
Character of the 42nd Avenue South Neighborhood
Residents are keenly aware of the beautiful new high school being built and they
believe it will set the tone for the entire neighborhood. There is strong
agreement that the street needs to retain its residential character: "It
shouldn't be an alternative to Highway 99." One person added that they don't
want to see any zoning,changes that will allow gas stations and convenience
stores. Several voiced concern about the changes they've seen in recent years,
including increases in vandalism, loitering and debris on the street.
General Attitudes toward 42nd South Street "Improvements"
The participants believe that the street improvements should be for local
residents who are paying taxes and not for people traveling through 42nd to other
destinations. All agreed with the statement that, "People who live here should
benefit from the improvements."
One woman had been to previous meetings involving changes to 42nd and explained
to the group that "improvements" could includes more sidewalks, pedestrian paths,
underground utilities and improved storm drainage.
The opinions expressed were unanimous that 42nd South should stay two lanes and
that the City should provide better enforcement of speeding laws and truck usage.
One person added that an additional "Free lane" would add more lanes of traffic
to the street and make it more difficult for many residents to get out of their
driveways. (Note: she lives near 154th.)
Current Concerns
Many of the concerns expressed deal with pedestrian safety issues. Those living
on 42nd say that speeding cars, lack of crosswalks, poor visability at some
intersections, low curbs at some intersections, lack of barriers where the road
curves and has sheer drop -offs, and poor lighting are all problems that need to
be resolved in the improvement project.
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CAROLYii BROWNE ASSOCIATES
Community Involvement / Marketing Research
42nd South Discussion - Page 2
The concerns brought up by discussion participants included:
Safety-concerns for school children: The elementary school was designed as
a "walk to" school, but increasing traffic is making the walk dangerous
for children. At 152nd, cars whip around corners and don't watch for
pedestrians. Many children walk from Thorndyke and Showalter. The corner
needs to be raised for safety.
The "speedway" from Southcenter: Many people coming up from Southcenter
are using 42nd to avoid traffic jam -ups on 1 -5. Residents don't want to
see any street widening which they believe will promote more traffic from
Southcenter.
Large trucks using 42nd: Many large trucks are illegally using the street;
the City needs to supply more enforcement of the 5 ton limit.
Too much traffic in general: Residents have noticed substantial increases
in traffic on the street, but few measures to improve pedestrian safety.
No place for bicycles: Bicycles don't go on 42nd because they can't.
Dangerous Pedestrian Area at 154th: One person said they have nearly been
hit at the intersection on several occasions and they've seen cars nearly
hit others. Drivers frequently don't make stop and just skip through
four -way stop. Many children use the intersection, and they have a
difficult time crossing the street. Several shared the concern that
someone will get seriously injured by cars speeding through.
Transitions to property: There are banks and steep slopes leading to many
driveways. The city will need to put in retaining walls or rockeries to •
keep yards and drainfields from sloughing off into the street. Many
property owners will also need good transitions built between the street
and their driveways. Four of the group members said there might be access
problems if the job is not done right.
What Shouldn't be Done
Many residents are anxious about the term, "street improvements," and they worry
that the city will add more lanes and increase the traffic on 42nd South. There
was strong agreement among the participants that, most importantly, 42nd should
remain a two -lane, residential street. •
One citizen described improvements done on 51st south of 160th and suggested
others go and look at the street, which she described as a "Very good looking
residential street."
Residents are also concerned that the improvements not take away parking.
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
42nd South Discussion - Page 3
What Residents Want Included in the Improvement Project
The residents want the improvements to focus on safety needs -- particularly for
pedestrians - -, resolution of drainage problems, nicely finished transitions
between the improvements and homeowner properties and undergrounding of the
utilities. The specific suggestions from the group included:
Sidewalks and /or Pedestrian Paths: The group divided on whether they
prefer full, cement sidewalks on both sides of the street or whether they
want a sidewalk on one side and a pedestrian path on the other. They
agree that one or the other is essential.
Good parking: Adequate parking needs to be provided for homeowners and
their visitors.
Retaining wall near 139th: A retaining wall is needed for safety along
42nd near 139th where the street curves down. Cars frequently speed
through the area and the curves are very dangerous.
Better drainage. Runoff comes down 152nd onto 42nd. After it rains there
is always water in front of the homes in this area.
Well- marked crosswalks are needed at 152nd and 154th: The crosswalks
should also have warnings to drivers about pedestrians. One man also
pointed out that there are too many trees on the corner at 150th, creating
blind spots for turns; the crosswalk at 150th is dangerous.
Traffic controls and enforcement are needed: It's a "Dragstrip" from 144th
to 154th; traffic controls are needed to slow down traffic. Signs which
say, "Speed limit 25 'when children are present'" is too vague." From
Foster High School down to 154th, cars go very fast. From 518, the very
steep hill causes a lot of speeding.
Attractive appearance: The street should be nice looking when the project
is finished including covering the ditches, undergrounding the utilities
and putting in curbed sidewalks.
Better Lighting: Better lighting is needed throughout the entire project
area. A combination of long blocks between cross - streets, many trees and
sparsely placed lights (which one person said are frequently burned out),
makes 42nd South "A very dark street."
It was suggested that when homeowners are contacted about meetings for the
project, the city should include the people who live in homes on the corner of
the streets that intersect 42nd. Some people have addresses on other streets,
but are still on 42nd. •
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CAROL 'N BROWNE ASSOCIATES
Community Involvement / Marketing Research
42nd South Discussion - Page 4
Concluding Comments: What are throe most important improvements?
Participants were asked, in turn, to name the three improvements that should have
the highest priority. The 12 members of the group shared many of the same
priorities.
The priorities for the group members are listed below followed by the number in
the group naming the same item:
Curbed sidewalks (6)
Install a signal at 154th (5)
Underground utilities (4)
Better pedestrian crossings /crosswalks (3)
Improved drainage (3)
Better street lighting (2)
Good driveway transitions, access to property, retaining walls (2)
Reduce speeds /enforce speed limits (2)
Pedestrian paths (2)
Adequate parking for residents (2)
Keep trucks off 42nd (1)
Retain residential character (1)
Questions for the City of Tukwila
Several questions were raised during and after the discussion. It's likely that
these same questions are in the minds,of many of the residents in the project
area:
1) Is it the policy of the city to do underground wiring when street
improvements are made? •
2) At the east side of 42nd at 152nd, there's a large piece of property with
a steep drop -off. Who will pay to bring property up to street level for
pedestrian path? There's also a natural waterflow coming into the ravine
that cannot be interfered with.
3) Will homeowners have the option to have the section in .front of their
house paved over rather than have gravel? Many homeowners will be willing
to pay for paving because they don't want gravel coming to the property
line.
4) What will happen to mailboxes? Who will pay for and arrange to move them?
There's currently a lot of vandalism of mailboxes; is there anything the
city can do to help?
5) Kids swing on the wires that hang at 152nd. Will these be going
underground?
6) What about major east -west streets between 138th and 154th? They are in
more need of repair than 42nd. They are narrow and have ditches and no
sidewalks.
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
42nd South Discussion - Page 5
Questions for the City - continued
7) Will it be an option for homeowners to work out a separate agreement with
the contractor to have their driveways blacktopped at the same time the
improvements are made.
8) Will the sidewalks be cement?
9) How will the city contact homeowners to let them know when construction
will start?
10) Some homeowners have not hooked up onto the sewer line and are still using
septic tanks. Will a sidewalk cover the stub for the hookup and make it
difficult for a homeowner to hook up to the sewer system at a later time?
11) What will the street improvement project cost the individual homeowner?
How will improvements be financed?
12) How much property will be cut into for each property owner?
13) Now much notice will the city give homeowners about work on the improve-
ments? It's important to have sufficient notice to plan gardening
activities.
14) For the public meeting, will the city supply ideas or have examples for
people to look at? One person suggested having a video tape of the
improvements made to 51st South.
15) What will be done with mailboxes when street is improved? Some don't want
mailboxes grouped because it will make it a long walk for some of the
property owners who have large pieces of property.
16) When will construction begin for improvements? What is the timeline for
entire project and what will be included?
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CAROLYZv BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
PUBLIC WORKSHOP: CONDUCTED AUGUST 14, 1991
TABULATIONS FROM GROUP DISCUSSIONS AND QUESTIONNAIRES
Introduction
Citizens living on or near 40th Avenue South and 42nd Avenue South, between East
Marginal Way and South 160th Street, were invited to attend a Public Workshop on
August 14, to discuss the 42nd Avenue South Improvement Project. Citizens were
informed about the meeting through letters mailed and hand - delivered to residents
in the project area, and from notices posted in the community.
The Workshop was held at the Tukwila Community Center from 7:30 to 9:00 p.m. The
meeting was facilitated by Carolyn Browne. Brief presentations were made by Ron
Cameron, the City Engineer, and by Rich Perteet, from Perteet Engineering. Ron
Cameron, Ross Heller and Rich Perteet responded to questions from citizens before
and after small group discussions.
Some 19 citizens attended the Workshop and participated in small group dis-
cussions responding to two questions:
1) What are the major concerns that should 'be addressed by the project?
2) What are the improvements for 42nd Ave. So. you want investigated?
After the discussion period, participants completed an Individual Questionnaire.
Summary of Themes from Discussion Worksheets and Individual Questionnaires
Group Discussions
The 19 participants formed three groups (two groups with seven each and one group
of five people). They were asked to "laundry- list" their responses to the two
questions; then prioritize, by selecting three most important items from each
list.
In the discussion groups, citizens provided a long list of concerns. Heading the
prioritized list were concerns about property restoration• and landscaping (12
gave it top priority), drainage problems (10) -and speeding problems and
pedestrian safety (8). Also important: concerns about property encroachment (7);
keeping the street narrow (6) and residential (4) and paying for the costs of
undergrounding utilities.
The improvements'most wanted included: Better street lighting (10), bicycle paths
(9), and adequate on- street parking .(7). They emphasized they do not want a
third lane or a swale.
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
August 14, 1991 Public Workshop Tabulations - Page 2.
Individual Questionnaires
All but one of those attending completed an Individual Questionnaire. Most of
those attending live on or near 42nd Avenue South, somewhere between 139th and
154th Streets; 10 live in the area between 150th and 154th.
All but two have lived at their present address for five or more years; seven
have lived in the current home for 30 or more years.
Most (14) learned about the meeting from a notice received in the mail (14) or
left on the door (5); some also learned about the meeting from a friend or
neighbor.
The most frequently mentioned concerns included drainage issues, access to their
property (several have steep driveways) and losing landscaping that has served
as a screen.
On the questionnaires, the need for sidewalks was the major improvement most
wanted (all but 2 rated this one of their three priority items); bike paths (9),
and improved drainage (8) rated high also. Other items which received priority
ratings from more than one or two individuals included: underground utilities
(5), on- street parking (4) and better street lighting (3).
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CAROLr ry BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
August 14, 1991 Public Workshop Tabulations - Page 3.
Group Worksheet Tabulations
Note: The number following each item represents the total number of participants
in all three discussion groups prioritizing the same item.
1. What are the major concerns that should be addressed by the project?
Property restoration /landscape 12
10
8
7
6
6
5
4
4
. 3
3
3
3
3
2
2
2
. 1
1
1
1
1
Excessive drainage
Safety - speeding, pedestrian safety
No property encroachment
Keep street narrow
Cost of undergrounding
Seattle City Light provides payment plan
Problem of low water pressure
Keep route residential
Access problems caused by swale in the street .
Lower speed limit
Aesthetics and stability of rockeries
Funding for driveway transitions
Maintain access to steep driveways
Water quality
Coordination of paving with utilities
Save trees
Garbage collection - where to put containers .
Location of mailboxes
Project justification
Improvement of side streets
Life of underground utilities
2. What are the improvements for 42nd Avenue So. you want investigated?
Street lighting
Bike paths
No third lane
Provide on- street parking
Swale (not very desirable)
Drainage
Sidewalks
More and better quality bus stops
Traffic signal on 154th
Underground bike tunnel at 154th
Stop signs and cross walk on 152nd
Underground utilities
Rockeries
Mailboxes
Handicap access
Mail drop
Maintenance /aesthetics
10
9
7
7
6
4
4
4
3
3
2 •
2
1
1
1
1
1
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
August 14, 1991 Public Workshop Tabulations - Page 4.
IndiVlfila7 Questionnaires
1. Please indicate the nearest cross- streets for your residence?
42nd Avenue So. and:
139th 2
140th 1
144th. 2
146th 3
150th 2
151st 1
152nd 5
154th 2
2. How long have you lived at your present address?
One year or less 2
Five to nine years 6
Fourteen to nineteen years 5.
Thirty or more years 7
3. How did you learn about tonight's meeting:
Notice received in mail 14
Notice left on door 5
Friend /neighbor 4
Other 1
4. If you have some specific concerns about how this
project may affect your property, please describe
them for us:
Drainage issues 6
Steep driveway /driveway access 5
Losing screening landscaping 3
Property will be too close to the road 2
Retaining wall will be needed 1
Parking 1
Safety in approach from driveway 1
Slow down speeding cars 1
Walkway - lighted to library and store 1
Would like to be contacted in person about concerns 1
Underground utilities 1
Sidewalk 1
Keep school district advised of construction
schedules etc. so that bus stops and routes
can be adjusted 1
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CAROLl -w BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
August 14, 1991 Public Workshop Tabulations.- Page 5.
5. If you were in charge of the street improvement project, but only had
the money for three major improvements, where would you spend the money?
Sidewalks 17
Bike paths 9
Drainage 8
Underground utilities 5
Parking 4
Better lighting 3
Ground water management 2
Safety • 1
Enforce speed laws 1
Mail boxes 1
New pavement 1
Retaining wall 1
Two car paths no third lane 1
Stop light on 144th 1
6. Additional comments or suggestions?
Better police patrol 2
Keep area residential 2
Appreciate request for input from citizens 2
Keep the community informed about meetings 1
Better lighting 1
Concerned about the amount of attention that will be
paid to citizen input 1
Improvements are not important 1
Concerned for the safety of children walking . . . 1
Need a full stop light on 154th 1
Strong publicity is needed for next public meeting 1
Concern about increased property tax, suggests
exemption for low income senior citizens 1
Turn 42nd into a residential street 1
Cost of underground utilities for those on 42nd
should be borne by Tukwila or King County residents 1
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
Summary of Responses to February Mail Survey
The City of Tukwila mailed out questionnaires to approximately 500 residents
living in the vicinity of the 42nd Avenue South project boundaries. A total of
62 respondents completed and returned questionnaires in time to be included in
these tabulations. An additional three questionnaires were returned too late to
be included in this summary, but their comments have been read by the Public
Works staff working on this project.
Questionnaires were tabulated based upon address location and whether respondent
lives on the east or west side of the street. '
Responses were generally well distributed all along the project area from S.
132nd to just south of S. 160th. There were some clusters of response at S.
142nd and just north of S. 158th.
Address of Respondents
Of the 62 questionnaires returned:
74% (46) reside on 42nd S. between S. 136th and S. 160th
8% (5) reside on 40th S. between S. 128th and S. 136th
13% (8) reside at other addresses on 40th S. or 42nd S.
5% (3) gave no address or live out of the area
44% (26) live on east side of street or east of project
56% (33) live on west side of street or west of project
Sidewalk Preferences
Most people want sidewalks, especially for the safety of the school children in
the community. Most prefer sidewalks on just one side of the street, but there's
a considerable split between which side would be better: 40% (25) favor sidewalks
on the east side, while 24% (15) want them on the west side; an additional 23%
(14) want them on both sides. Just four people (6 %) said they want no sidewalks
and another four people didn't respond to the question.
Residence
Total East Side West Side
Preferred location of sidewalks:
East side only 40% 35% 49%
West side only 24 31 15
Both sides of street 23 19 27
No sidewalks 6 11 3
No response 5 4 6
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CAROL -rl BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Improvement Project
Mail Survey Summary - Page 2.
Parking Preference
Residents .who responded to the survey are considerably divided in their opinions
about parking, although the highest proportion of responses (27 %, or 17) do not
want any additional parking on the street. Some 26€ (16) said they favor
locating the parking wherever possible without impacting driveways or front
yards. Only 8% (5) want parking on both sides, while 16% (10) want parking on
just the west side and 8% (5) want parking on just the east side. Several people
(10% or 6) did not respond to this question. Many of those apposed to additional
parking say they are concerned about safety (i.e. visibility) when they exit from
their driveways.
Residence
Total East Side West Side
Preferred parking:
No more on- street parking 27% 38% 21%
Wherever possible 26 31 24
West side only 16 11 21
Both sides 8 8 6
East side only 8 4 . 9
No response 10 0 18
Additional Comments
Several people commented that they like the fact that there's currently not much
on- street parking and they appreciate the improvements that have already been
made by the city. They also commented about the current lack of traffic on the
street.
When asked to describe some improvements they want to see made, the greatest
proportion (16% or 10) said they want sidewalks, especially for the school
children. Many (13% or 8) asked the City to retain, or provide additional,
parking. Several also asked for enforcement of speeding laws and said the street
is fine as it is and they don't want any more improvements. Many added their
concern that any additional improvements might encourage greater use of the
street. Other improvements suggested included: underground utilities, better
lighting and repaving of the street, cover drainage ditches and take measures to
reduce traffic on the street.
Residence
Total East Side West Side
What is liked about street:
Not much street parking 13% 11% 154
Like improvements already made 10 8 12
Not much traffic 6 15 0
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CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd Avenue South Irprovement.Project
Mail Survey Summary - Page 3.
Residence
Total East Side West Side
What would make street better:
Sidewalks /sidewalks for children 16% 12% 18%
More parking /retain parking 13 19 3
Reduce speeds /enforce speed laws 11 15 .9
Fine as is /don't make improvements 11 11 9
Underground utilities 8 7 9
Better lighting 6 0 12
Resurface street /improve paving 5 7 3
Cover drainage ditches 5 0 9
Less traffic 5 7 3
Additional comments:
Have stop at S. 158th
Improve pedestrian safety
Passing lane going uphill
No overnight street parking
People. in parked cars are nuisance
Ban large trucks
Remove "No parking" signs on new walking lane & have limited parking on lane
Remove hump in front of mailboxes
Underground wiring
Traffic interrupter islands from S. 140th to S. 154th, except at S. 144th
and S.154th, to reduce speeds and volume
Less abrupt transition from street to driveway on west side
Add 4 -way stop at 42nd S. and S. 150th
Parking on west side should be limited to certain number of feet from
driveways for safety
Stop light at 42nd S. and S. 154th
There will be more accidents if parking is allowed between S. 160th and S.
154th
Add 4 -way stop at 42nd S. and S. 160th
Cannot get out of driveway between 3:00 and 6:00 because of too much traffic
Home has been burglarized several times
Live at the top of the curves; very dangerous to exit from driveway
Need parking for visitors
Make it wider
16
1
*OM
S. 1267H ST
• S. 144TH ST.
S. 146TH ST.
S. 148TH ST
S. 150TH ST.
046
S. 152ND STU
S. 154TH ST.
S. 160TH ST.
111
S. 158TH ST.
S. 160TH ST.
-TLIKVIX L." 41 2P10 AN/ ZNUIE MOUTH
SNP. HOU le 114 EMT' POO
L000lVion oV Roopoo
17
TUKWZ LA 4ZNO AVENUE 304.1TN
SMPROVEMENT PROJECT
Preferred Parking
AO No parking /no additional parking
D Parking on east side only
a Parking on west side only
❑ Parking needed on both sides
L Parking wherever aoprooriate
S. 153TH ST.
S. 160TH ST.
S. 16.tT1-1 ST.
I
18
12oTa C-
S. 126TH ST.
S. 130TH ST.
S. 123TH ST.
D
51.
S. 134TH ST.
0
S. 139TH ST. 0
•
•
S. 140TH ST. •
D❑
S. 1 =1ST ST. •
Q•
• 04
S. 144TH ST.
0
S. 142ND ST.
S. 146TH STRii
5. U3TH STl ,
a
D
S. 150TH ST.
S. 152ND ST
S. 154TH ST.
S. 160TH ST.
.
TUKWILA 42ND AVENUE SOUTH
IMPROVEMENT PROJECT
Preferred Sidewalks
• No sidewalks /no additional sidewalks
D Sidewalks on east side only
Q Sidewalks on west side only
0 Sidewalks on both sides
S. 15.31.:-4 5T.
S. 160TH ST.
S.164TH ST.
19
CAROLYN BROWNE ASSOCIATES
Community Involvement / Marketing Research
TUKWILA 42ND AVENUE SOUTH IMPROVEMENT PROJECT
PUBLIC WORKSHOP: FEBRUARY 27, 1992
Introduction
Over 500 residents and property owners in the project area received a mail survey
and an invitation to attend the second Public Workshop, held on February 27,
1992, at the Tukwila Community Center.
Of the 30 citizens who attended the workshop, most had completed and returned the
written questionnaire to the City. Eleven people completed a questionnaire
distributed at the workshop.
At the meeting, citizens were invited to view exhibits illustrating design
concepts for improvements to 42nd Avenue South and 40th Avenue South within the
project boundaries. Members of the consultant team and Tukwila Public Works
Department staff responded to the questions and concerns of individuals before
and after a presentation to the group. Questions from the group were also
answered.
Summary of Concerns Expressed
The comments and concerns expressed at this meeting generally were the same as
those heard at the focus group discussion, at the first public workshop and in
the responses to the mail survey. Most importantly, people want to see the
residential character of the street maintained and they want a safer environment
for pedestrians including sidewalks, crosswalks in appropriate areas and signals
where warranted. They also want the drainage problems resolved, enforcement and
design elements that will reduce speeds in the area and better lighting.
Tabulations from Individual Questionnaires
1. Did you complete and return the Citizen Survey that was distributed to
residents in the area at the beginning of February?
No 6
Did not receive a survey 5
2. What special character, if any, does this street have that you want to see
preserved?
Residential character 6
No response 2
Leave as. it is 1
Not much traffic from "99" 1
Room for residents to park 1
2 0'
CAROIAL„ BROWNE ASSOCIATES
Community Involvement / Marketing Research
Tukwila 42nd So. Improvement Project
February 27, 1992 Public Workshop
Meeting Summary - Page 2
3. What are the improvements you believe are most needed on the street?
Sidewalks /safety of school children 8
Sidewalks - eastside (high school)
Steep, icy spot at 136th 1
Traffic control /slow down traffic 2
Stop lights
Needs to be repaved . 1
Underground wiring 1
Some on- street parking 1
Crosswalks by library (142nd) 1
Level the street from 144th to 154th 1
4. Do you believe there should be sidewalks on both sides or one side of the
street, or should there be no sidewalks in the project area?
Sidewalks on both sides 4
Sidewalks on east side only 5
Sidewalks on west side only 1
Not sure 1
5. Should the street be widened to allow parking on both sides of the street
or just one side or should.it be left the way it is now?
Parking on both sides of the street 3
Parking on west side only 1
No more parking on the street 3
Not sure 2
Parking both sides where needed only 2
Concern about location of sidewalk
near apt. complex (142nd & 42nd) 1
Concerned about steep driveway access 1
6. If you have any other concerns about this street improvement project,
please describe these concerns for us:
Surface water management /storm sewers 1
Don't make speed trap 1
Have plenty of street lighting 1
Lost parking at Normandy Court Apts. 2
Busy street; ideas are good and will
help 1
Do not need to widen 42nd S. 1
Poor work on street last fall 1
No safe crossing at 150th & 42nd 2
21
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