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Lower Urban Speed Limits are a Win for the Climate – Yale Climate Connections

Photo by Rick Rotondo, Borough of Phoenixville

Since 2015, Seattle has lowered speed limits across much of its road network, setting residential streets at 20 miles per hour and most larger urban corridors at 25 miles per hour. After these changes took effect, studies showed that car crashes fell by approximately 20%, while the crashes that did occur resulted in significantly fewer injuries.

Cities across the U.S. are following Seattle’s lead, with speed limits dropping from Denver and Minneapolis to Washington, D.C., and Hoboken. Although these changes are motivated by the need to reduce deaths and injuries from car crashes, there’s a growing recognition that they also benefit the climate.

“Safety and environmental goals go together. They’re inevitably interlinked,” said Venu Nemani, the chief safety officer of the Seattle Department of Transportation.

Transportation is the largest source of emissions in the United States, and passenger vehicles are the leading offenders within the sector. Electric vehicles can help reduce these emissions, but they’re not a silver bullet — many experts agree that meeting climate targets will also require car use to fall. As a result, it’s vital for governments to help people meet their needs by walking, cycling, and taking public transportation (which often requires traveling on foot to a transit stop).


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