1

NE 125th Street Rechannelization Before and After Report

Project Goals

Improvetrafficsafety

Increasecompliancewiththespeedlimit

Improvepedestrianandbicycleaccess

Project Outcomes

Declineintherateoftotalcollisionsand injurycollisions

Reductioninthenumberofpeopleexceeding speedlimit

Reductioninpedestrianandbicyclecollisions

Background

InMay,2011theSeattleDepartmentofTransportationreconfiguredthelanesonNE125thStreetbetweenRooseveltWayNEand30thAvenueNEtomakethestreetsaferforeveryone,supportbuses,andmaketrafficflowmoresmoothly.Priortotherechannelizationthereweretwotravellanesineachdirection.Thestreetwasreconfiguredtoprovideonelaneineachdirection,anewtwo-wayleftturnlane,andbicyclelanes.SDOTagreedtomonitortheproject’simpactonsafetyandtrafficaftertherechannelizationwascompleted.

NE 125th Street Before

NE 125th Street After

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NE 125th Street Rechannelization Before and After Report

Speed

Speeddataismeasuredatthespeedmostdriversarecomfortabledriving(the85thpercentile),thenumberofdriversexceedingthespeedlimit(30mph)andthenumberofaggressivespeeders,ordriversexceedingthespeedlimitbyatleast10milesperhour(40mph).Highspeedscanbeakeycontributingfactortothecollisionandinjuryratesoncitystreets.Highspeedsreducedriverawareness,andcreatemoreseverecollisions.Forexample,ifavehiclehitsapedestrianwhilegoing40milesperhourthepedestrianhasaslimchanceofsurvival.Reducingvehiclespeedgreatlyimprovespedestriansafety.

SDOTmeasuredspeeddatanear20thAvenueNE.Thelocationisfiveblocksfromthefullsignalat15thAvenueNEandfiveblocksfromthepedestriansignalat25thAvenueNE.Priortotheproject,the85thpercentilespeedwas41mpheastbound(whichisdownhill)and39mphwestbound(uphill).Eighty-sevenpercentofdriversweretravelingoverthespeedlimit.16percentofdriverswerespeedingat40mphormore-morethan10mphoverthespeedlimit.

Sincetheprojectwascompleted,mostdriversarestillabletotravelatorabovethespeedlimit.The85thpercentileisnow38mpheastboundand36mphwestbound.Therehasbeenan11percentdecreaseinthepercentageofpeopleexceedingthespeedlimit.Andtherehasbeenanevenmoredramatic69percentdecreaseinthepercentofdriversspeedingmorethan10milesoverthespeedlimit.

Theseaggressivespeedersaremostlikelytocausedeathorinjuryintheeventofacollision.

Thefactthatmostdriverscontinuetoexceedthespeedlimitindicatesthattraffichasnotcometoastandstillbutrathercontinuestobefree-flowingmostoftheday.

NE 125TH STREET SPEED

BEFORE AFTER CHANGE

85th Percentile 40.0 36.9 -8%

Eastbound 41.4 38.0 -8%

Westbound 38.6 35.7 -8%

Driving Faster Than 30 87% 77% -11%

Eastbound 92% 85% -8%

Westbound 83% 68% -18%

Driving Faster Than 35 51.6% 29% -44%

Eastbound 62.3% 38.6% -38%

Westbound 40.8% 19.5% -52%

Driving Faster Than 40 16% 4.9% -69%

Eastbound 22.4% 7.3% -67%

Westbound 9.5% 2.5% -74%

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NE 125th Street Rechannelization Before and After Report

Volume

Aftertheprojectwascompleted,motorvehicletrafficonNE125thStreetincreasedsignificantlybetweenLakeCityWayand30thAvenueNE.Furthereasttrafficvolumeisroughlythesameasitwasbeforetheproject.Takentogether,thedataindicatesthattrafficvolumeoverallhasincreasedroughly10percentonNE125thStreet.OnepossiblefactorinexplainingthisincreasemaybetrafficdiversionsimmediatelyfollowingtheintroductionoftollingontheSR520floatingbridge.TollingbeganonthatbridgeinDecember,2011–andthegreatestincreaseintrafficon NE125thStreetappearedimmediatelyaftertollingbegan.

NE 125TH STREET MOTOR VEHICLE VOLUME

Between Lake City Way & 30 Avenue NE

June 2009 January 2012 Change

DailyWeekday 11,089 14,819 +34%

AMPeakHour 364 527 +45%

PMPeakHour Westbound

485 717 +48%

NE 125TH STREET MOTOR VEHICLE VOLUME

Between 26th Avenue NE & 27th Avenue NE

September 2009 February 2013 Change

DailyWeekday 16,209 15,574 -4%

AMPeakHour 518 536 +3%

PMPeakHour 720 722 (<)+1%

PedestrianandbicyclevolumewascountedattheintersectionofNE125thStreetand30thAvenueNE.ThecountswereconductedonMarch16,2005andagainatthesamelocationonJanuary31,2012. Onbothdays,rainwasrecordedinSeattle.BothbicycleandpedestriancountstendtobelowerinthewintersothissnapshotprovidesaconservativeestimateofthenumberofpedestriansandbicyclesusingNE125thStreet.

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NE 125th Street Rechannelization Before and After Report

NE 125TH STREET BICYCLE AND PEDESTRIAN VOLUME

5-hour Count (7-9am; 1-2pm; 4-6pm)

March 16, 2005 January 31, 2012 Change

HighTemp56Precipitation0.14”

HighTemp49Precipitation0.03”

Bicyclesalong NE125thStreet

7 15 +114%

Pedestriansin thecrosswalks

330 676 +105%

Thelargeincreaseinpedestrianandbicyclevolumemaybepartiallyexplainedbynearbylandusechanges.Thenortheastcornerofthisintersectionwasredevelopedin2007andBartellsDrugStoremovedtothatlocation.TheLakeCityBranchofSeattlePublicLibrary,whichisoneblockaway,wasexpandedandremodeledin2005.

LakeCityisdesignatedanUrbanVillagebytheCityofSeattle.UrbanVillagesareexpectedtoabsorbmostofthegrowthinpopulationandjobs.AccordingtotheSeattleDepartmentofPlanningandDevelopment(DPD),thenumberofjobsinLakeCitygrew20percentbetween2004and2010.ThepopulationofLakeCitygrew43percentbetween2000and2010–aratemuchhigherthanthecitywide8percentpopulationgrowthduringthesameperiod.Accordingtoa2012reportbyPugetSoundRegionalCouncil,thepopulationofLakeCityisanticipatedto

growanother30percentandemploymentby85percentby2040.TheadditionaltripsgeneratedbymorepeopleworkingandlivinginLakeCityarelikelytoresultinevengreaterincreasesinthenumberofpeoplewalkingandbikingalongNE125thStreetinthefuture.

Collisions

Therateofcollisionsandtherateofinjurycollisionshavedeclinedsincetheprojectwascompleted.Thenumberofinjurycollisionspermonthdecreased.Themostpronounceddeclinesoccurredincollisionsinvolvingpeoplewalkingorbikingandfatalityandhead-oncollisions.Despitetheincreaseintrafficvolume,therateofcollisionshasdecreasedby10percent.ThesefindingsaresimilartoarecentFederalHighwayAdministration(FHWA)study(“EvaluationofLaneReduction‘RoadDiet’MeasuresonCrashes”)whichstudied30streetreconfigurationsinWashingtonandCaliforniaandfounda19percentreductioninthecollisionrateafterconversionfromfour-lanetothreelaneroadwayconfiguration.

COLLISION RATE

Before After Change

Collisionsper millionvehicles

5.83 5.24 -10%

Injurycollisions permillionvehicles

2.41 1.99 -17%

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NE 125th Street Rechannelization Before and After Report

Conclusions

ReconfiguringthelanesonNE125thStreethasmadeitsaferforeveryonetravelingalongthisstreet.Thesafetybenefitisespeciallyprominentforpeoplewalkingandbiking.Theprojectdramaticallyreducedthenumberofpeoplewhoaredrivingmorethan10milesoverthespeedlimit.Evenastrafficvolumehasincreased,therateofcollisionshasfallen10percent.Bicycleandpedestrianvolumehasincreasedalongthisstreetanditisexpectedtoincreaseevenmoreinthecomingyearsasthecitygrows.Theprojectaffordstheopportunitytoinstallnewmarkedcrosswalks–somethingSDOTisplanningtodoat20thAvenueNEadjacenttoachurchandpreschool.Thenewconfigurationofthestreetgivespeopleadditionalchoicesforhowtogetaround.Anditprovidesanadditionalwaytoencouragenewtripstobemadebywalking,bikingandtakingtransit.