Seattle’s Playful Traffic Circles Tame Neighborhood Streets

Seattle traffic circle 3

Last week, Dongho Chang, Seattle’s chief transportation engineer, posted a series of photos on Twitter of the city’s traffic circles. These neighborhood traffic-calming treatments are so charming, we had to post them here.

Seattle started installing traffic circles in the early 1970s, and now there are more than 1,200 throughout the city, says Chang. Seattle DOT’s traffic circle program typically adds them to intersections in residential areas with no traffic lights or stop signs, though some have replaced stop signs on low-traffic streets at crossings with larger streets.

The circles compel drivers to slow down while approaching intersections, and they’ve made a big difference. “They are installed to address angle collisions, and we typically look for two collisions within the past three years as a basis for considering them,” said Chang. A 1997 study by the city found that the traffic circles reduced collisions causing injury 97 percent and all collisions 90 percent.

Neighborhoods can request traffic circles from the DOT. Because demand is so high, the city prioritizes intersections with safety problems, Chang said.

Each traffic circle costs about $20,000 to design and construct. Crews remove pavement to allow street trees and other vegetation to grow from soil beneath the surface of the street. The city leads the process of landscaping, often in cooperation with neighborhood residents, which is why you see so many creative touches.

The result is an effective, practical, and beautiful way for cities to improve traffic safety on residential streets.

Photo: Dongho Chang, City of Seattle

traffic ricle 5

 

Seattle Traffic circle 4

Seattle traffic circle

Seattle traffic circle 1

 

ALSO ON STREETSBLOG

In Philadelphia, crashes declined 24 percent after stop signs replaced signals at 200 intersections. Image: Google Street View

To Make Streets Safer, Seattle May Get Rid of Traffic Signals

|
Signalized intersections carry special risks. Drivers often accelerate during the yellow phase to "beat the light," for instance, leading to high-speed crashes. Federal officials warn that improperly placed signals can "significantly increase collisions." So Seattle is reviewing 10 intersections to see if traffic signals should be replaced with stop signs.

America Could Have Been Building Protected Bike Lanes for the Last 40 Years

|
Salt Lake City is on track to implement the nation’s first “protected intersection” — a Dutch-inspired design to minimize conflicts between cyclists and drivers at crossings. For American cities, this treatment feels like the cutting edge, but a look back at the history of bike planning in the United States reveals that even here, this idea is far from new. In fact, […]

8 Monster Interchanges That Blight American Cities

|
Ramming highways through the middle of American cities was undoubtedly one of the worst mistakes of the 20th century — demolishing urban habitat, dividing neighborhoods, and erecting structures that suck the life out of places. What could be worse than a highway through the middle of town? How about when two highways intersect, with all […]

How Smart Language Helped End Seattle’s Paralyzing Bikelash

|
Michael Andersen blogs for The Green Lane Project, a PeopleForBikes program that helps U.S. cities build better bike lanes to create low-stress streets. Instead of “cyclists,” people biking. Instead of “accident,” collision. Instead of “cycle track,” protected bike lane. It can come off as trivial word policing. But if you want proof that language shapes […]