Somerville to Shrink Powder House Traffic Circle

In the next few weeks, the City of Somerville will use quick-build materials to transform the Powderhouse Circle traffic rotary, a six-way junction of busy walking and biking routes at the southern edge of the Tufts University campus, into a smaller roundabout with protected bike lanes, shortened crosswalks, and increased space for pedestrians.

The current Powder House Circle is the junction of several key neighborhood bike and pedestrian routes in western Somerville, including College Avenue, which runs through the Tufts campus to Davis Square, Broadway, Powder House Boulevard, and Warner Street, which connects to Main Street in South Medford half a mile away.

In spite of the neighborhood’s foot traffic, though, the traffic circle’s current design features long pedestrian crossings and wide driving lanes that invite higher speeds and allow aggressive drivers to swerve around slower-moving traffic.

Somerville’s new plan will attempt to retrofit the traffic rotary into a modern roundabout, with a smaller radius in the central circle, narrower entry and exit lanes, shorter crosswalks, and a new protected bike lane around the outer perimeter.

As we reported here last week, similar changes that were made to Kelley Square in Worcester have coincided with a dramatic reduction in the number of crashes in the intersection.

A city website for the project describes it as “a transformative quick-build project that will improve safety and predictability.”

A before-and-after rendering illustrates how, from a driver’s perspective, new paint and bollards will narrow drivers’ pathways through the circle, with the aim of improving visibility for bikes and pedestrians and slower speeds among motor vehicles:

The transformation of Powder House Circle complements other traffic-calming improvements that are in the works for connecting streets.

The City of Somerville is also installing new traffic-calming measures on an adjacent section of College Avenue this summer after a pickup truck driver struck and killed Dr. Leah Zallman in a College Avenue crosswalk last fall.

The College Avenue project will install new speed bumps, bike lanes, curb extensions, and bus prioritization lanes between Powder House Circle and Davis Square.

And in 2019, Somerville also installed new traffic calming measures and painted bike lanes to Powder House Boulevard in response to a motorist’s killing of Allison Donovan, a longtime educator for Watertown Public Schools, in a crosswalk in front of West Somerville Neighborhood School.

Arah Schuur, one of the founders of Somerville Bike Safety, expressed enthusiasm for the city’s Powder House Circle plans in a phone call with Streetsblog on Tuesday, and expressed her hopes that the city will extend the project’s new protected bike lanes further up adjacent streets, including Powder House Boulevard.

“It’s terrific that the city is doing this as a quick-build project,” said Schuur. “Paint isn’t protection, so it’ll be interesting to see how drivers respond, and whether this transforms into something more permanent in the longer term. But in general it should be very complementary to the city’s other work being done in the neighborhood this summer.”