At the intersection of Southern Avenue and Whitfield Street in Boston, Massachusetts, there was a documented history of cars speeding through the intersection instead of slowing down when entering the residential area. This tight, urban environment needed a solution to set the tone and slow drivers entering from a major arterial at higher speeds.


While speeds could potentially slow with the addition of a stop sign at the intersection, a fully raised center island is more effective when it comes to promoting slower speeds. Kittelson found a way to build a miniature roundabout that takes the shape of a comma to achieve residential speeds. This “comma-about” fits within the right-of-way of the roadway and allows the same movements of the intersection, as one of the streets is a one-way street. The new addition can also be landscaped to add the element of streetscape, making the area safer for other modes of travel.

Image of

Comma-about during construction

The Outcome

The First Ever "Comma-about"


Now, with drivers approaching and navigating Boston’s first-ever “comma-about”, safety is improved for people walking, biking, and driving through the intersection, returning the neighborhood streets to the neighbors.




Boston, Massachusetts