Traffic Operation Performances at Roundabout Weaving Sections

Abstract There are frequent confluence and diffluence operations at roundabout weaving sections. The operation performances are complicated because the entry vehicles of turn-left and run-straight travel around the circle center. On the basis of the Shuma square in Dalian city roundabout survey using video cameras, some parameter performances were analyzed, which included the velocity distribution, the distance distribution of lane changing, the headway distribution of confluence vehicles, and vehicles on circulating lanes, as well as the application of accepted headways. Besides, some conclusions were drawn, for example, the vehicle velocity of outer circulating lane is larger than the inner circulating lane; the confluence vehicle velocity is smallest; the diffluence operation occurs later than the confluence operation; the confluence vehicle velocity has a tendency to increase with the accepted headway increase; the posterior gap is usually larger than the frontal gap in one accepted headway; the equivalent critical gap of multilane roundabouts is smaller than the critical gap of single-lane roundabouts.