Roundabout Resources

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What is a Roundabout?

The modern roundabout is an unsignalized, circular intersection engineered to maximize safety and minimize traffic delay. Drivers travel counterclockwise around a central island. The entering traffic yields to traffic already in the roundabout, which keeps traffic from locking up and creates efficient traffic flow.

How to Drive in a Roundabout

Slow before entering. This allows you to anticipate gaps in traffic, and lets drivers in the roundabout know you are preparing to yield.
Yield to drivers circulating from the left. Look left for vehicles before reaching the yield line. If no vehicles are coming from the left and no pedestrians are in the crosswalk, there is no reason to stop.
Once you are in the roundabout, you have the right of way and entering traffic must yield to you.
Stay to the right of the central island. Traffic moves counterclockwise in a roundabout.
Watch for bicycles and pedestrians when exiting the roundabout, and use your right turn signal to indicate you are exiting.

How to Drive in a Mini-Roundabout

Yield on entry and move in a counterclockwise direction, just like a full-size roundabout.
Use a turn signal before entering a mini-roundabout if turning left or right onto a side street. If continuing on the same street, no signal is needed.
Signaling before entering improves efficiency because of the tighter constraints and shorter reaction times compared to a full-size roundabout.

Mini-Roundabouts vs. Full-Size Roundabouts

Mini-roundabouts function just like full-size roundabouts, but are used where space doesn't allow for a full-size modern roundabout.
Mini-roundabouts have a smaller footprint and can often be constructed within an existing intersection.
Mini-roundabouts have a smaller, paved central island with a lower curb. This allows long vehicles that require a large turning radius, like a semi or bus, to drive over the central island.
Full-size roundabouts have larger, landscaped central islands which are not traversable.