Traffic characteristics of mixed traffic flow in roundabouts

Roundabouts are widely used in urban areas. Current designs of roundabouts, such as speed limit and lane markings, are based on automobile traffic, and motorcycles and scooters traffic are not considered in details. For some cities where the usage of motorcycles is high, the design and evaluation approach may not be appropriate. This study investigates the traffic characteristics of mixed traffic flow in roundabouts. A microscopic traffic dataset is collected from a roundabout in Hsinchu City, Taiwan. The mixed traffic characteristics, such as speed profiles, trajectories, lane usages, curvature of trajectories etc., are analyzed. Our preliminary results show that there are significant differences in terms of speed distribution and lane choices between motorcycles and passenger cars at different locations of a roundabout.