Crunching the Safety Data Reveals the Need to Improve Traffic Lights

After completing an eight-year study of traffic collisions, the Seattle Department of Transportation realized that one way to immediately improve traffic safety would be to improve signalization an key intersections.

1 minute read

November 15, 2016, 1:00 PM PST

By James Brasuell @CasualBrasuell


Traffic Lights

Horia Varlan / flickr

Ryan Packer reports on a new commitment in Seattle to reprioritize traffic light replacements as a component of the Seattle Department of Transportation's (SDOT) Vizion Zero initiative. Here Packer sets the context:

When the Seattle Department of Transportation (SDOT) announced the end of an eight-year study on traffic collision data, it had a very comprehensive set of data on where collisions took place, what modes were involved, and how the collisions occurred. The big question was: how would the department begin to apply the data across the city to reduce those collisions?

Packer follows up a post on the SDOT Blog announcing that the agency has targeted traffic signalization as a priority project in response to the data produced by that study. "Not only will they be using that more robust set of data to determine where to add signals, they will also be prioritizing the improvement of existing traffic signals to improve the left turn movements," according to Ryan Packer. SDOT has already identified ten highest priority intersections for new traffic signals. According to Packer, the whole process reflects "a big step toward a data-driven approach to the day-to-day business that SDOT engages in all the time: routine maintenance, system upgrades, and safety improvements."  

Monday, November 14, 2016 in The Urbanist

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