Research Article

The Surrogate Safety Appraisal of the Unconventional Elliptical and Turbo Roundabouts

Table 1

Details of double-lane roundabouts simulated.

Number of lanesTypes of roundaboutSpeed limits[km/h]Traffic lightCentral island radii[m]Total Traffic Volume[veh/h]Max Capacity

Two lanesTurbo50AbsenceMain radius R=56m3040veh/h3480veh/h
Two lanesElliptical50AbsenceMain radius R=56m
Secondary radius r=23m
2400veh/h3000veh/h