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HomeMy WebLinkAboutTrans 2016-06-20 Item 2B - Discussion - Thorndyke School Zone Speed StudyCity of Tukwila Allan Ekberg, Mayor INFORMATIONAL MEMORANDUM TO: Transportation Committee FROM: Bob Giberson PE, Public Works Director BY: Scott Bates, Traffic Engineering Coordinator CC: Mayor Ekberg DATE: June 17, 2016 SUBJECT: Thorndyke School Zone Speed Study ISSUE Present the results of the Thorndyke Elementary school zone speed study conducted as part of the Safe Routes to Schools grant program and Radar feedback sign installations. BACKGROUND Staff conducted a before and after speed study to document the effects of the driver feedback speed radar signs installed as part of the Safe Routes To Schools grant program. Two radar speed signs were installed at the existing school zone sign locations on 42nd Ave S at approximately 400 feet south and approximately 300 feet north of S 150th St. The feedback speed signs display the approaching vehicle's speed as it enters the school zone to increase driver awareness. ANALYSIS The before and after speed study data collection utilized pneumatic tubes near the sign locations before the radar speed signs were installed and again several weeks after the signs were activated. Analysis of the measured speeds show a 12% increased compliance rate in vehicle speed for the northbound direction and 19% in the southbound direction. Additionally, staff observations indicate that the driver feedback signs appear to provide a higher level of awareness of speeds which should correlate to overall improved school zone safety. DISCUSSION Another set of movable radar speed signs have been ordered and will be installed temporarily in other areas of concern, in no particular order: S 160th Street (4600 Block), 51St Ave S (16400 Block), Ryan Way, S 144th St (4600 Block), 42nd Ave S (11900 Block), S 124th (4400 Block), 58th Ave S, S 130th, S 140th, etc. The movable signs will be installed and moved roughly every 30 days after speed data is gathered in dark mode (measuring but not displaying a feedback speed) then in active speed sign mode ( "your speed is... "). A pilot project to install traffic calming devices on S 160th St is in the planning stage and more details will be brought back to Committee in advance of any construction on 42nd Ave S (S 160th to Southcenter Boulevard) as an attempt to dissuade bypass traffic patterns. RECOMMENDATION Information Only. Attachments: Traffic count spreadsheets and comparison graphs 17 Thorndyke School Zone Speed Study Northbound Before 06:00 07 :00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 mph 0-151 16 -20 I 21 -25 I 26 -30 I 31 -35 I 36 -40 I 41 -45 1 46 -50 I 51 -55 I 56 -60 I Total I Total After 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 Total 00 3 6 34 51 5 16 85 147 3 23 64 91 2 4 14 51 0 6 18 53 4 7 32 64 7 0 22 78 4 3 36 95 6 16 57 87 8 90 9 9 51 112 7 12 68 121 4 17 51 101 62 143 609 1141 24 77 70 52 41 40 37 45 71 65 43 44 44 44 45 641 16 4 8 12 10 6 4 19 14 6 6 6 5 116 0 1 1 1 2 3 0 1 0 0 0 0 1 10 0 0 1 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O 180 O 310 O 232 O 124 O 126 O 161 O 183 0 223 O 223 O 249 O 231 O 258 O 224 0 2724 mph 0 -15 16 -20 21 -25 26 -30 31 -35 36 -40 41 -45 46 -50 51 -55 56 -60 Total 1 4 42 49 74 9 0 0 0 0 179 3 57 154 65 34 1 0 1 0 0 315 12 58 111 49 10 4 0 0 0 0 244 8 14 48 63 17 2 0 0 0 0 152 2 19 55 38 28 5 0 0 0 0 147 4 11 53 70 26 0 0 0 0 0 164 6 14 76 68 26 3 1 0 0 0 194 3 15 48 86 35 4 0 0 0 0 191 5 29 76 95 26 5 0 0 0 0 236 4 51 109 57 22 0 0 0 0 0 243 3 35 114 83 35 4 1 0 0 0 275 8 35 123 98 41 4 0 0 0 0 309 2 17 76 107 48 5 0 0 0 0 255 61 359 1085 928 422 46 2 1 0 0 2904 1200 1000 800 600 400 200 0 mph 0-15 16 -20 Thorndyke School Zone Speed Study Northbound Speeds before 900 800 700 600 500 400 300 200 100 0 mph 0-15 16-20 21 -25 26 -30 21 -25 26 -30 31 -35 36 -40 Speeds after 31 -35 36 -40 41 -45 46 -50 41 -45 46 -50 51 -55 56 -60 5155 56 -60 1200 1000 800 600 400 200 0 mph 0 -15 Thorndyke School Zone Speed Study Southbound Speeds before 900 800 700 600 500 400 300 200 100 0 mph 0 -15 16 -20 16 -20 21 -25 26 -30 21 -25 26 -30 31 -35 36 -40 Speeds after 31.35 36 -40 41 -45 46-50 41 -45 46 -50 51 -55 56 -60 5155 56 -60 Thorndyke School Zone Speed Study Southbound Before 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 mph 0-151 16 -20 I 21 -25 I 26 -30 I 31 -35 I 36 -40 1 41 -45 I 46 -50 I 51 -55 I 56 -60 I Total I Total After 3 3 2 0 0 1 1 0 1 15 4 12 1 43 0 2 11 4 1 4 3 4 8 21 6 13 5 82 9 37 48 15 7 13 27 21 35 76 42 78 44 452 23 66 67 36 42 55 67 59 84 127 143 146 97 1012 43 29 31 38 39 46 64 62 49 47 117 94 84 743 13 5 2 8 5 9 15 16 5 4 13 10 9 114 2 2 0 2 2 0 2 2 2 1 1 0 1 17 0 0 0 0 1 1 0 0 0 0 0 0 1 3 0 1 0 0 1 0 1 0 0 0 0 0 0 3 0 93 O 145 1 162 O 103 O 98 O 129 O 180 O 164 O 184 O 291 O 326 O 353 0 242 1 2470 mph 0-151 16 -20 I 21 -25 1 26 -30 I 31 -35 I 36 -40 I 41 -45 I 46 -50 I 51 -55 1 56 -60 I Total ! 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 Total 0 7 14 36 28 7 0 0 0 0 92 2 22 52 47 14 3 0 0 0 0 140 4 38 77 51 9 3 0 0 0 0 182 2 11 31 41 24 1 0 0 0 0 110 1 11 35 34 20 2 1 0 0 0 104 3 12 44 56 24 2 0 0 0 0 141 4 10 58 58 27 1 0 0 0 0 158 0 12 41 51 27 1 0 0 1 0 133 2 23 59 71 17 7 0 0 0 0 179 21 81 103 73 16 0 1 0 0 0 295 9 42 140 125 32 2 0 0 0 0 350 3 33 128 119 65 4 0 0 0 0 352 5 14 60 90 59 7 1 1 0 0 237 56 316 842 852 362 40 3 1 1 0 2473