Traffic Calming

Seattle has been calming traffic since 1978. Since then, the Seattle Department of Transportation (SDOT), in partnership with residents, has been involved in the installation of thousands of traffic circles, speed humps and other traffic calming devices. The purpose of these traffic calming devices has been to reduce collisions and speeds on residential streets, thereby creating safer and more pleasant neighborhoods. 

In 2015, SDOT piloted 20 mph zones. As part of that pilot program, numerous traffic studies were completed and we found that most people traveled under the speed limit when the street is 25 feet wide and there is parking on both sides of the street.This data helped lower the speed limit on all streets in the City.

Limited traffic calming dollars are focused on areas that have no curbs and limited sidewalks, typically in high equity areas near schools. These funds are allocated to the neighborhood via the Home Zone Program

If you are interested in traffic calming solutions for your neighborhood, there are some low cost options summarized below.

  • Yard Signs: Yard signs are intended to inform drivers that they are travelling on a neighborhood street and remind drivers to slow down. 
  • Parking Management: Parking on both sides of the street can be an effective traffic calming tool. On wide open streets, some drivers can feel comfortable traveling at higher speeds.  Narrower streets encourage drivers to slow down.  

Home Zone Program

If you have concerns beyond speeding on your street, including cut-through traffic, you and your neighbors may want to look into other solutions in the Home Zone Program. 


Greg Spotts, Director
Address: 700 5th Ave, Suite 3800, Seattle, WA, 98104
Mailing Address: PO Box 34996, Seattle, WA, 98124-4996
Phone: (206) 684-7623

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The Seattle Department of Transportation (SDOT) is on a mission to deliver a transportation system that provides safe and affordable access to places and opportunities for everyone as we work to achieve our vision of Seattle as a thriving, equitable community powered by dependable transportation.