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Home My WebLink AboutTrans 2013-07-23 Item 2C - Discussion - 42nd Avenue South/Allentown Roadside Barrier Warrant AnalysisTO: City of Tukwila Jim Haggerton, Mayor INFORMATIONAL MEMORANDUM Mayor Haggerton Transportation Committee FROM: Bob Giberson, Public Works Director DATE: July 19, 2013 SUBJECT: 42nd Ave South /Allentown Roadside Barrier Project No. 91310301 Warrant Analysis ISSUE Discuss draft barrier warrant analysis for 42nd Ave South in Allentown. BACKGROUND The Transportation Committee requested a study regarding guardrail and /or barrier warrants along 42nd Ave South in Allentown. As existing concrete barriers wrap around onto S 115th St from 42nd Ave S, this additional area was also included in the study area and then extends to the 42nd Ave S Bridge. ANALYSIS The goal of the study was to identify applicable design and safety standards, identify roadside barrier needs, and identify any upgrades or modifications to existing guard rail and concrete barriers. Based on Washington State Department of Transportation (WSDOT) and American Association of State Highway and Transportation Officials (AASHTO) standards, several areas of the river bank along 42nd Ave S and S 115th St are being recommended for guardrail or barrier installation and /or upgrades and modifications (see pages 4 and 5 of the report and the plans in Appendix A). The estimated construction cost for all recommended guardrail and barrier installations is $271,460, and with preliminary engineering (20 %) and construction management (15 %), the total project cost estimate is $366,480. Additional funding will be needed for the Small Roadway and Safety Improvements CIP Residential Street Program. Funds could be spread over the next 6 years to minimize the impact to the Residential Street Fund (103 Fund). RECOMMENDATION For discussion only. Attachments: Draft 42'd Ave S Barrier Warrant Analysis Draft 2014 CIP page for Small Roadway & Safety Improvements 7 W ,PW EngtPROJECTSW- RW & RS Projects\42nd Ave S Allentown Roadside Bamer {913103011' Info Memo 42nd Ave S Barrier draft report gl.docx Technical Memorandum To: Bob Giberson, P.E. Public Works Director, City of Tukwila 6300 Southcenter Blvd, Suite 100 Tukwila, WA 98188 CC: Nelson Davis, P.E. From: Andrew Merges, P.E. Date: 6/19/2013 Re: 42nd Ave S — Roadside Barrier Warrant Analysis Project No: City # 91310301.1000.100 (KPG # 13093) This technical memorandum consists of providing a roadside barrier warrant analysis and recommendations for barrier placement on the south side of S 115th Street (adjacent to the fire station) and the west side of 42nd Ave S (from S 115th Street to S 124th Street), see vicinity map attached. Washington State Department of Transportation (WSDOT) and American Association of State Highway and Transportation Officials (AASHTO) guidelines have been utilized to determine applicable barrier warrants, however due to the low volume and speed of the roadway, 25 miles per hour, the analysis can be subjective in nature. The three primary goals of the analysis are: • Identify applicable industry design standards to form a baseline for barrier warrant within the project limits. • Identify roadside barrier needs within the project limits • Identify modification or upgrades to existing roadside barriers. Project Description The project study area along S 115th Street and 42nd Ave S is adjacent to the Duwamish River, bordering both on the south and west sides of the roadway. The roadway is generally flat with no substantial grades and is located vertically fifteen to twenty plus feet above the water surface present during site reconnaissance on June 7th, 2013. Existing grades of the river bank range from 4' H:1' V and steeper with the majority of the grades exceeding 1.5' H:1' V based on visual inspection. It should be noted that there is typically two slopes that constitute the river bank, the first being steep from the surface of the water to an assumed seasonally high water mark, and then one less steep to the edge of roadway. In a few isolated locations, there also appears to be circular arc failure of the river bank. 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 8 ICPC1. Existing roadway channelization is present along S 115th Street that delineates edge lines and centerline raised pavement markings Existing channelization along 42nd Ave S consists of center line raised pavement markings and curb and gutter on the east side of the roadway. No channelization currently exists on the west side of 42nd Ave S. There is also no established roadway shoulder along the roadway(s), only informal gravel parking areas where adequate width is available. It appears that there have been recent sidewalk and curb and gutter improvements along the east side of 42nd Ave S, terminating at the beginning point of curvature as the roadway transitions to S 115th Street. It appears that the centerline at this location is inconsistent, introducing an offset of the southbound traffic as they exit the curve onto 42i1 Ave S. Existing roadside barriers are present in some locations along both S 115th Street and 42nd Ave S. The utilization of semi- ridged beam guardrail and rigid unrestrained concrete barriers are located at tee - intersections, adjacent to roadway curves, adjacent to selected fixed objects (trees), and selected locations of steep river bank where no shoulder exists. No rigid anchored barriers or impact barrier were observed. Roadside Barrier Design Warrants and Limitations Roadside barriers are designed to restrain and /or redirect vehicles that leave the delineated traveled way with the assumption that the systems implemented are not guarantees of their performance in all situations. The WSDOT Design Manual and AASHTO Roadside Design Guide have been used to develop site specific criteria due to the low posted speed of 25 MPH on 42nd Ave S and S 115th Street. While there are a few roadside obstacles such as trees and utilities that impose a safety concern for motorists, the primary focus is on the proximity of the Duwamish River as a permanent body of water. In this instance, AASHTO recommends that the placement of barriers is warranted based on "judgment decision based on location and depth of water and likelihood of encroachment" (AASHTO, 5 -5). After site review of the project area, the following criteria for barrier analysis are determined to be applicable: • Duwamish River bank considered non - recoverable. • Clear zone /shoulder assuming a relatively flat slope (6'H: 1'V or flatter) from edge of pavement and /or traveled way to top of river bank is 10' for roadways less than 35 miles per hour (WSDOT, 1600 -15) While AASHTO's clear zone ranges from 12' -14' for speeds 40 mph or less given an ADT of 1500 -6000 (AASHTO, 3 -7), WSDOT's 10' clear zone has been used due to the region's accepted general design practices. • In all cases where embankments are steeper than or equal to 3'H:1'V and the vertical height of the section exceeds 10 -feet, barriers are warranted (AASHTO, 5 -3). Within this analysis, this is applied to embankments within the clear zone where recoverable slopes may be present. • Fixed objects within the clear zone must be protected. Page 12 753 9t" Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 9 P Roadside Barrier Design Standards and Types While there are not as well developed guidelines for roadside barrier designs for roadways with speed limits of 25mph, WSDOT and AASHTO do provide basic design parameters for various types installed. In general, each barrier placement must be designed for the specific site constraints and usually one detail, especially for this project, may not be adequate. For example, there are different lengths of guardrail posts that can be used for various applications. Many factors can be considered when selecting a roadside barrier such as economics, aesthetics, performance, and maintenance. Due to the close proximity of the river banks, barrier performance characteristics in regards to longitudinal barrier deflection is considered the overriding concern. The typical barrier options reviewed per the WSDOT Design Manual with their design deflection characteristics are (WSDOT, 1610 -8): • Cable Barrier or Beam Guardrail (Type 20, 21 on G -2 posts) o Type: Flexible o Deflection: Up to 12 -feet (face of barrier to object) • Beam Guardrail (Type 1, la, 2, 10, and 31) o Type: Semi -rigid o Deflection: Up to 3 -feet (face of barrier to object) • Permanent Concrete Barrier, Unanchored o Type: Rigid, Unrestrained o Deflection: Up to 2 -feet (back of barrier to object) • Precast Concrete Barrier, Anchored o Type: Rigid, Anchored o Deflection: Up to 6- inches (back of barrier to object) • Rigid Concrete Barrier o Type: Rigid o Deflection: No Deflection A second design criterion for barrier selection is the shy distance available, or the distance from the edge of traveled way to the face of barrier. Typically, barriers should be placed as far as possible from the traveled way as possible in order to allow errant motorists opportunity to regain control of their vehicle. When site constraints limit distances from the traveled way, a 3.6 -foot shy distance is recommended. For barriers with continuous long runs, this distance may not be as critical and may not adversely affect driver speeds or lane positions. Guardrail post depth is a third barrier characteristic considered for this project. The WSDOT Design Manual figure Exhibit 1610 -11 illustrates type 31 beam guardrail post installation based on backslopes of no steeper than 1'H:1'V starting at the face of guardrail. Guardrail depths can vary from 6 feet to 11 feet. It is anticipated that post between 8 to 11 feet would be needed for all guardrail recommended. Page 13 753 9t" Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 10 Recommendations After site review of existing conditions within the project limits as well as the above established warrants and criteria for evaluating roadside barrier need, there is the need for new barrier installation as well as barrier replacement and/or modifications. For the majority of situations, it is anticipated that beam guardrail type 31 with long posts can be utilized for the project, even in cases where there is recommended concrete barrier removal /replacement. Appendix A contains plan sheets illustrating barrier recommendations for the project site and they are summarized in the following table. BEGIN STA END STA EXISTING BARRIER TYPE ACTION PROPOSED BARRIER TYPE MEASURED LENGTH 10' CLEAR ZONE 5 +00 9 +00 - - - 300' YES 9 +00 11 +15 CONCRETE UNRESTRAINED REMOVE REPLACE GUARDRAIL 215' NO 11 +15 13 +30 - INSTALL NEW GUARDRAIL 222' NO 13 +30 13 +70 CONCRETE UNRESTRAINED REMOVE REPLACE RESTRAINED BARRIER 40' NO 13 +70 19 +00 CONCRETE UNRESTRAINED REMOVE REPLACE GUARDRAIL 530' NO 19 +00 22 +00 GUARDRAIL CHECK POST DEPTHS REPLACE IF NEEDED 300' NO 22 +00 24 +20 - INSTALL NEW GUARDRAIL 220' NO 24 +20 29 +65 - - - 545' YES 29 +65 31 +30 - INSTALL NEW GUARDRAIL 165' NO 31 +30 32 +10 - - - 80' YES 32 +10 34 +90 - INSTALL NEW GUARDRAIL 280' NO 34 +90 35 +45 - INSTALL NEW RESTRAINED BARRIER 55' NO 35 +45 38 +45 - INSTALL NEW GUARDRAIL 300' NO 38 +45 38 +75 CONCRETE UNRESTRAINED - - 30' YES 38 +75 40 +75 - INSTALL NEW GUARDRAIL 200' NO Page 1 4 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 11 KPG BEGIN STA END STA EXISTING BARRIER TYPE ACTION PROPOSED BARRIER TYPE MEASURED LENGTH 10' CLEAR ZONE 40 +75 45 +55 - - - 480' YES 45 +55 45 +85 CONCRETE UNRESTRAINED - - 30' NO 45 +85 46 +95 - INSTALL NEW GUARDRAIL 110' NO 46 +95 49 +30 - - - 235' YES 49 +30 49 +30 GUARDRAIL REPLACE TERMINAL NEW TERMINAL - NO As shown on the plan sheets, there are situations where there is recommended concrete barrier removal and replacement. This is primarily due to the barriers being unrestrained, their proximity to the edge of pavement, and in some cases the erosion of existing material under the barrier that serves as a base. In the event of vehicular collision, there is the possibility of the barrier overturning and sliding on the adjacent slope that would create a non - recoverable condition. A geotechnical survey of existing river bank stability and associated guardrail post embedment is also recommended due to visual observations of embankment failure. Short -term roadway improvements that could also provide additional roadway safety, but not substitute for roadside barriers include: • Ensure roadway has center and edge line delineation. • Correct centerline channelization for 42nd Ave S at the beginning point of curvature as the roadway transitions to S 115th Street. • Add edge of pavement reflective delineation on the east side of 42nd Ave S and the south side of S 115th Street. Profiled edge lines or flexible, reflective posts could be used. • Installation of edge of roadway rumble strips if pavement width permits. Engineer's Opinion of Probable Constriction Cost An Engineer's Opinion of Probable Construction Cost has been developed based on the barrier recommendations above and is located within Appendix B. The assumptions that have been made in order to determine the costs include: • Type 31 guardrail would be utilized with wood long posts. • Restrained barrier would be jersey type with anchors. Page 15 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 12 P • Existing barrier between STA 19 +00 to 22 +00 remains in place and not included for removal /replacement. If modifications are required, an additional $20,000 could be assumed for this work. It should be noted that WSDOT is transitioning to steel posts for guardrail due to variability in service life of wood posts. An economic life cycle cost study was performed by WSDOT and the resulting increase in costs to use steel is approximately 13% (Smith). For this study and project area, it was assumed that wood posts would be sufficient. Page 6 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 13 Vicinity Map f. ..R SIM PROJECT LOCATION BA ter irnelioNo MEM wvipmrannzavgai A 4-11111?4. al Pa c 7 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 14 PEP References American Association of State Highway and Transportation Officials (AASHTO). Roadside Design Guide 3rd Edition 2006, with updated Chapter 6. Washington: 2006. Smith ST. Economic evaluation of treated wood and galvanized steel guardrail posts. WSDOT; 2013. 8p. Washington State Department of Transportation (WSDOT). Design Manual M 22- 01.08. Olympia: WSDOT Publication Services, 2011. Page 8 753 9th Avenue North, Seattle, WA 98109 P: 206.286.1640 F: 206.286.1639 www.kpg.com 15 Appendix A Plans .dwg 6/13/2013 K: \PROJECTS \TUKWILA \13093 -42nd Ave S \DESIGN \Drawings \C MATCH LINE STA 6 +00 SHEET 0 MATCH LINE STA 10 +50 THIS SHEET PLAN 0 10 20 40 SCALE IN FEET MATCH LINE STA 10 +50 THIS SHEET MATCH LINE STA 15 +00 SHEET 2 CONSTRUCTION NOTES 0 REMOVE AND REPLACE GUARDRAIL TERMINAL LEGEND PROPOSED GUARDRAIL I PROPOSED CONCRETE BARRIER �TITT/ ti REMOVE EXISTING BARRIER PUBLIC' WORKS DEPT_ * ENGINEERING *STREETS *WATER* SEWER *BUILDING * designed drawn checked prof eng proj dir field bk no by xxx xxx xxx xxx date xx xx xx xx IKPQ 75391hAvenue N Seattle, WA 90109 (206) 286-1640 www.kpg.corn 2502 Jefferson Avenue Tacoma, WA 98402 (253) 627 -0720 42ND AVE S. ROADSIDE BARRIER WARRANT ANALYSIS BARRIER PLAN STA 6 +00 TO STA 15 +00 J 1 5 file no 13093PLN.DWG no date revisions scale 1" = 46' date 6/2013 J K: \PROJECTS \TUKWILA \13093 -42nd Ave S\ DESIGN \Drawings \Contract \13093PLN.dwg 6/19/2013 MATCH LINE STA 19 +50 THIS SHEET MATCH LINE STA 15 +00 SHEET 1 MATCH LINE STA 19 +50 THIS SHEET MATCH LINE STA 24 +00 SHEET 3 CONSTRUCTION NOTES 0 REMOVE AND REPLACE GUARDRAIL TERMINAL LEGEND PROPOSED GUARDRAIL I PROPOSED CONCRETE BARRIER �TITT/ ti REMOVE EXISTING BARRIER PUBLIC WORKS DEPT_ * ENGINEERING *STREETS *WATER* SEWER *BUILDING * designed drawn checked proj eng proj dir field bk no by xxx xxx xxx xxx date xx xx xx xx KPQ 753 9th Avenue N Seattle, WA 96109 (206) 286-1640 *e .kpg.can 2502 Jefferson Avenue Tacoma, WA 98402 (253) 627 .0720 42ND AVE S. ROADSIDE BARRIER WARRANT ANALYSIS BARRIER PLAN STA 15 +00 TO STA 24 +00 2 5 file no 13093PLN.DWG scale 1" = 40' no date revisions date 6/2013 K: \PROJECTS \TUKWILA \13093 -42nd Ave S\ DESIGN \Drawings \Contract \13093PLN.dwg 6/19/2013 MATCH LINE STA 24 +00 SHEET 2 MATCH LINE STA 28 +50 THIS SHEET PLAN 0 10 20 40 SCALE IN FEET MATCH LINE STA 28 +50 THIS SHEET CONSTRUCTION NOTES 0 REMOVE AND REPLACE GUARDRAIL TERMINAL LEGEND I I PROPOSED GUARDRAIL PROPOSED CONCRETE BARRIER REMOVE EXISTING BARRIER PUBLIC WORKS DEPT_ * ENGINEERING *STREETS *WATER* SEWER *BUILDING * designed drawn checked proj eng proj dir field bk no by xxx xxx xxx xxx date xx xx xx xx KPQ 753 9th Avenue N Seattle, WA 96109 (206) 286-1640 *e .kpg.corn 2502 Jefferson Avenue Tacoma, WA 98402 (253) 627 -0720 42ND AVE S. ROADSIDE BARRIER WARRANT ANALYSIS BARRIER PLAN STA 24 +00 TO STA 33 +00 3 5 file no 13093PLN.DWG scale 1" = 40' no date revisions date 6/2013 J G 26/ MATCH LINE STA 33 +00 SHEET 3 MATCH LINE STA 37 +50 THIS SHEET SCALE IN FEET -W- I W 120 MATCH LINE STA 37 +50 THIS SHEET MATCH LINE STA 42 +00 SHEET 5 CONSTRUCTION NOTES 0 REMOVE AND REPLACE GUARDRAIL TERMINAL LEGEND PROPOSED GUARDRAIL I PROPOSED CONCRETE BARRIER �TITT/ ti REMOVE EXISTING BARRIER PUBLIC' WORKS DEPT_ * ENGINEERING *STREETS *WATER* SEWER *BUILDING * designed drawn checked proj eng prof dir field bk no by xxx xxx xxx xxx date xx xx xx xx IKPQ 753 9th Avenue N Seattle, WA 98109 (206) 2861640 www.kpg.cam 2502 Jefferson Avenue Tacoma, WA 98402 (253) 627 -0720 42ND AVE S. ROADSIDE BARRIER WARRANT ANALYSIS BARRIER PLAN STA 33 +00 TO STA 42 +00 110 date revisions 4 5 file no 13093PLN.DW scale r' = 40' date 6/2013 ract \13093PLN.dwg 6/19/2013 11:09 AM K: \PROJECTS \TUKWILA \13093 -42nd Ave S \DESIGN \Drawings \C MATCH LINE STA 42 +00 SHEET 4 MATCH LINE STA 46 +50 THIS SHEET SCALE IN FEET MATCH LINE STA 46 +50 THIS SHEET MATCH LINE STA END SHEET 6 CONSTRUCTION NOTES 0 REMOVE AND REPLACE GUARDRAIL TERMINAL LEGEND I I PROPOSED GUARDRAIL I PROPOSED CONCRETE BARRIER tTTITT/ ti REMOVE EXISTING BARRIER PUBLIC' WORKS DEPT_ * ENGINEERING *STREETS *WATER* SEWER *BUILDING * designed drawn checked proj eng prof dir field bk no by xxx xxx xxx xxx date xx xx xx xx IKPQ 753 9th Avenue N Seattle, WA 96109 (206) 286-1640 ww o.kpg.com 2502 Jefferson Avenue Tacoma, WA 98402 (253) 627 -0720 42ND AVE S. ROADSIDE BARRIER WARRANT ANALYSIS BARRIER PLAN STA 42 +00 TO STA END 5 5 file no 13093PLN.DWG scale r" = 40' no date revisions date 6/2013 J Appendix B Cost Estimate PROJECT COST ESTIMATE KPH SFATTt.[ •TAC MA PROJECT: 42nd Ave S - Roadside Barrier Warrant Analysis DATE: 6/19/2013 Description Quantity Unit Unit Cost Total 1 Mobilization 2 Construction Surveying 3 Project Temporary Traffic Control 4 Type 31 Guardrail - Long Post (Wood) 5 Restrained Barrier 6 Guardrail Terminal 7 Remove Existing Barrier 8 River Bank Stabilization 9 Pavement Markings 10 Temporary Erosion Control 1 LS $ 15,000.00 $ 15,000.00 1 LS $ 3,000.00 $ 3,000.00 1 LS $ 8,000.00 $ 8,000.00 2242 LF $ 40.00 $ 89,680.00 95 LF $ 45.00 $ 4,275.00 8 EA $ 2,500.00 $ 20,000.00 785 LF $ 20.00 $ 15,700.00 1 LS $ 60,000.00 $ 60,000.00 1 LS $ 7,500.00 $ 7,500.00 1 LS $ 3,000.00 $ 3,000.00 Subtotal Cost $ 226,160.00 30% Contingency $ 45,300.00 TOTAL CONSTRUCTION COST $ 271,460.00 Survey, Design, Permitting, Management $ 54,300.00 Construction Management and Inspection $ 40,720.00 TOTAL ENGINEERING & ADMINISTRATION COST $ 95,020.00 TOTAL PROJECT COST $ 366,480.00 1 of 1 24 PROJECT: DESCRIPTION: JUSTIFICATION: STATUS: CITY OF TUKWILA CAPITAL PROJECT SUMMARY 2014 to 2019 Small Roadway and Safety Improvements Project No. Varies Programmatic approach to addressing small roadway and safety concerns through a variety of methods. Addresses needs not included in general maintenance, traffic calming, or other approaches. Increasing public demand on staff time. Local accesstsidential neighborhoods may need minor roadway or safety improvements that can not be addr any other City program. 42nd Ave S /Allentown Roadside Barrier i§..p' MAINT. IMPACT: Minimal. COMMENT: Full program is only feasible if Pula .corks adds a Traffic Engineer to staff (same position as Traffic Calming). FINANCIAL Through Estimated in $000's 2012 2013 2014 2015 2016 2017 2018 2019 BEYOND TOTAL EXPENSES Design 50 10 10 10 10 10 100 Land (R/W) 0 Const. Mgmt. 10 10 10 10 10 10 60 Construction 50 50 50 50 50 50 300 TOTAL EXPENSES 0 0 110 70 70 70 70 70 0 460 FUND SOURCES Awarded Grant 0 Proposed Grant 0 Mitigation Actual 0 Mitigation Expected 0 City Oper. Revenue 0 0 110 70 70 70 70 70 0 460 TOTAL SOURCES 0 0 110 70 70 70 70 70 0 460 2014 - 2019 Capital Improvement Program 5 25