Simple Street Change Saves Pedestrian Lives

Blog posted On October 10, 2018

Pedestrian traffic deaths reached a 25-year high last year.  According to the Governors Highway Safety Association almost 6,000 pedestrians were killed in 2017.  The US Department of Transportation (DOT) is working to reverse this figure with a simple street redesign currently popping up at intersections in New York City, San Francisco, and Los Angeles.  By adding rubber bumpers to intersections, drivers who are turning left are forced to slow down, and even lessen the sharpness of their turn, reducing the risk of vehicle-pedestrian Collison. 

After studying over a thousand traffic-crash reports, researchers found left-turning vehicles were responsible for three times as many pedestrian and cyclist casualties as right-turning vehicles.  

Why are left turns so dangerous?

  • Poor visibility – increases likelihood of the crash
  • Higher speed – makes crashes more dangerous
  • Cutting corners – puts vehicles in the crosswalk

When a driver is turning left, the car’s frame obstructs the driver’s view more than in right turns, they tend to accelerate into the turn because they have a wider turning radius than right turns, and they usually cut corners.  The DOT is experimenting with adding low-cost bumpers to intersections instead of undergoing extensive redesigns that involve expanding lanes, pouring concrete, or installing additional traffic signals.  A basic hardened centerline slows drivers and prevents them from cutting corners, slow turn wedges provide a flexible buffer between pedestrian traffic and vehicle traffic, and a complete hardened centerline combines elements of each design. 

DOT officials analyzed traffic-crash data to determine which intersections were at the highest risk of collisions.  Since 2016, the DOT has updated 217 intersections and found a significant drop in left-turn crashes.  Though the program is still in its early stages, DOT officials are optimistic these small changes will have a lasting impact.


Sources: NPR, Quartz