How did the Bicyclist Cross the Road? By: Mike Hendrix, PE, PTOEDate: June 26, 2012 A Case Study of Two Intersections in Seattle

Seattle Bike Master Plan  A blueprint for making improvements to Seattle’s bicycle network  Adopted in 2007  Seattle BMP Goals: Triple bicycling by 2017 Reduce bicycle collisions by 1/3 between 2007 and 2017

Seattle Bike Master Plan  Seattle BMP Accomplishments: Installed 129 miles of on-street facilities including bike lanes and sharrows Added over 9 new miles of multi-use trail improvements Implemented 98 miles of signed bicycle routes Installed over 2,200 bicycle parking spaces

Case Study What?  Analysis of 2 intersections before and after signal installation  Both intersections were along a neighborhood greenway  Signals weren’t warranted based on MUTCD criteria Why?  To determine if the traffic signals installed along this neighborhood greenway improved conditions – for ALL users

Case Study  Determined changes in volumes  Determined changes in collisions  Observed operational issues

Background Unwarranted signals are BAD. They:  Increase collisions  Increase red-light running  Increase delay  Increase noise and air pollution  Lead to increased maintenance costs  Lead to a potential increase in cut-through traffic

Background  2011 Pinellas County Study: 273% annual increase in collisions  2008 Kentucky Study: 28.3% increase in collisions 221.7% increase in rear-end collisions  1989 New York City Study: 65% increase in collisions  1979 Purdue University Study 3,200 to 4,200 vehicle hours of delay

General Site Conditions

Site 1 Fremont Ave N & N 80th St  Fremont Ave N – 25’ wide residential street  N 80 th St – 1 lane each direction with on-street parking on north side  15,500 vpd (N 80 th St)  700 vpd (Fremont Ave N)  Signal turn-on 11/16/2007

Site 2 Fremont Ave N & N 105th St  Fremont Ave N – 25’ wide residential street  N 105 th St – 2 lanes each direction with no on-street parking  23,000 vpd (N 105 th St)  900 vpd (Fremont Ave N)  Signal Turn on 10/7/2010

Signing and Markings Span Wire SignPavement Marking

Pre-Signal Conditions

Pre-Signal Warrant Summary At N 80 th StreetAt N 105 th Street Signal WarrantsNot Met PHB WarrantsNot MetMet Caltrans Bike WarrantNot Met

Fremont & N 80th St Before Collision History 3 Years Before Correctable Crashes11 Non-Correctable Crashes2 Crash Rate (Crashes per MEV) Severity Index1.77

Fremont & N 105th St Before Collision History 3 Years Before Correctable Crashes3 Non-Correctable Crashes5 Crash Rate (Crashes per MEV) Severity Index1.25

Delay Intersection Pedestrian Delay (seconds) Motor Vehicle Side Street Delay (seconds) Bikes as Motor Vehicles Side Street Delay (seconds) Bikes as Pedestrians Side Street Delay (seconds) NBSBNBSB Fremont Ave N & N 80 th St Not Available52.2 Fremont Ave N & N 105 th St 5,

Post-Signal Conditions

Post-Signal Warrant Summary At N 80 th StreetAt N 105 th Street Signal WarrantsNot Met PHB WarrantsMet Caltrans Bike WarrantNot MetMet

Fremont Ave N & N 80th St After Collision History 3 Years Before3 Years After Correctable Crashes110 Non-Correctable Crashes23 Crash Rate (Crashes per MEV) Severity Index

Fremont Ave N & N 105th St After Collision History 3 Years Before1 Year After Correctable Crashes30 Non-Correctable Crashes51 Crash Rate (Crashes per MEV) Severity Index

Volume Changes Intersection BicyclistsPedestriansMotor Vehicles BeforeAfterBeforeAfterBeforeAfter Fremont Ave N & N 80 th St N/A Fremont Ave N & N 105 th St

Operational Issue: Violations Fremont Ave N & N 80th St  NB: 12.8% (23 cars)  SB: 14.1% (22 cars) Fremont Ave N & N 105th St  NB: 13.5% (38 cars)  SB: 12.9% (30 cars)

Operational Issue: Hot Spot Marking Fremont Ave N & N 105th St  27 of 232 (11.6%) bicyclists went directly for pedestrian push button. Fremont Ave N & N 80th St  Roughly same proportion

Summary  Neither signal met 2009 MUTCD signal warrants. Both met PHB warrants in the after condition.  Collisions and collision rates decreased at both signals following signal installation.  Severity of collisions at both signals decreased following the signal installation.

Summary  Bike and pedestrian volumes increased while motor vehicle volumes remained relatively constant.  Significant portion of motorists observed violating turning restrictions.  Observed significant misunderstanding of “Hot Spot” markings by bicyclists.

Thank you for your time! Questions? Contact Information Mike Hendrix, PE, PTOE