Number of deadly car crashes, injuries has dipped since Seattle lowered speed limits
SEATTLE — A new study shows there have been fewer injuries and deadly crashes on Seattle streets since the city lowered speed limits.
While it may be common knowledge that traveling at high speeds on state highways increases the risk of car crashes, researchers at the Insurance Institute For Highway Safety (IIHS) specifically focused on the importance of reducing speed limits on residential streets as well.
Its new report looks at 2016, when city officials lowered the default speed limits from 30 mph to 25 mph on its arterial roads and from 25 mph to 20 mph on smaller, mostly residential streets
To make drivers aware of the change, the city conducted a public outreach campaign and installed gateway signs.
“When we talk about the safe system approach, we always stress that nobody should have to die because of a mistake,” IIHS President David Harkey said. “These results illustrate the value of rethinking speed limits. Crashes still happened after Seattle’s changes, but they weren’t as dangerous.”
Researchers say they looked at the proportion of crashes involving fatal, serious or evident injuries, comparing the before-and-after injury rates with three control cities in Washington where there were no known changes to speed limits over the study period.
According to their findings, crash injuries in Seattle decreased by 17% on downtown roads and 20% on arterial roads in the three years following the speed limit changes.
“These results suggest that communities can reap substantial benefits by lowering speed limits,” said IIHS senior research transportation engineer Wen Hu, the lead author of the study. “To reduce injuries even further, communities should combine lower speed limits with engineering solutions, public education about the importance of reduced speeds and high-visibility enforcement.”
The Seattle Department of Transportation said over the past couple years, it has installed thousands of new 25 mph speed limit signs across the city. More than 90% of city streets have that posted limit.
