Roundabouts

Frequently Asked Questions

Roundabout design features

Is the roundabout like a four-way stop?

Not really. The main similarity is that both roundabouts and four-way stop intersections do not have signals. The differences include: four-way stops yield to whoever arrives first, or the vehicle on the right, roundabouts yield to the left---like a right turn on red---because the circulating traffic comes from that direction. At four-way stops, each direction gets a turn in order. At roundabouts, each driver chooses a safe gap to enter and no driver "gets a turn."

Center Island

The circular central island around which traffic circulates; this island may be raised or flush with the roadway surface; a mountable/drivable truck apron may surround the center island; the truck apron accommodates the path of the rear left wheels of larger vehicles such as semi-tractor trailers, farm equipment, buses, etc.; the truck apron is generally constructed with a different material to discourage passenger vehicles from driving over it.

Circulatory Roadway/Circulating Lanes

The roadway around the central island on which circulating vehicles travel in a counterclockwise direction, entering and exiting only to the right.

Splitter Island

A raised or painted island separating entering and exiting traffic and placed within a leg of a roundabout; the splitter island also serves to deflect and slow entering traffic, as well as provides a refuge/safety zone for crossing pedestrians.

Yield Line

A broken line marked across the entry roadway where it meets the outer edge of the circulatory roadway and where vehicles wait, if necessary, for an acceptable gap to enter the circulating flow; if no traffic is in the roundabout, entering traffic may proceed without stopping.