What is a Roundabout Turning Count?

A roundabout turning count is more complex than most junction turning counts since there can be multiple roads entering and exiting the intersection.

Traditionally vehicles are tracked from entering the roundabout through circulation until they exit. Roundabout turning counts can be difficult and more expensive because of the size of the roundabout, vision obstacles and the continuous flow of traffic. Because the entering flow combines with circulating traffic and leaves the roundabout at different exit points manual counts are really only suitable for low traffic roundabouts. There can be errors because observers have to remember the origin of the vehicle when recording exit data.

For improved accuracy video based counts are usually preferred. The cameras used need to be placed in good vantage points and may need image calibration.

Aerial footage can also be useful for some roundabout turning counts.