City Traffic: Circular Questions

The City of Richmond is considering whether to create an additional four roundabouts at various traffic choke points in the city. Such traffic circles make good sense as a general rule. They are not appropriate everywhere.

Roundabouts tend to be much safer than four-way perpendicular intersections and old-fashioned traffic circles. Roundabouts involve one-fourth as many vehicle-to-vehicle conflict points, and one-third as many vehicle-to-pedestrian conflict points, as four-way intersections. Because they require slowing down and yielding to enter the flow of traffic, they are safer than the old-fashioned traffic circles such as the Lee Circle on Monument Avenue. Roundabouts tend to reduce congestion as well.

Yet they have drawbacks. Although roundabouts are smaller than traditional traffic circles, they can require more space than four-way intersections -- first for the central island, and second for the lane flaring required at entry points to allow for merging.

This would seem to present a problem especially at one of the Richmond sites being considered: Forest Hill and Roanoke, where the intersection is hemmed in by apartment buildings and private residences on one side, and Forest Hill Park (newly refurbished at some expense) on the other. Much of the delay in the area is caused by the narrow bottleneck between Roanoke and the light where Forest Hill, Semmes, and Dundee intersect, where traffic must pass over a two-lane bridge beside the Crossroads coffee parlor. (The bus stops at Roanoke also impede flow.) It could be a close call deciding whether a roundabout at the T-shaped intersection would be a real boon -- or just a boondoggle.