A Simulation Study of Path and Speed Through Double-Lane Roundabouts

This study assessed the effects of geometric curvature and lane demarcation on drivers’ selection of path and speed in double-lane roundabouts. By means of a PC-based simulator, path and speed data were collected as subjects drove twice through six roundabouts. The six roundabouts varied in terms of pavement markings and geometric curvature on the entry and exit. Seventy-five participants were tested using a fixed-base driving simulator. The results showed that drivers maintained lane position better when the roundabouts had lane demarcation than when the roundabouts had no lane demarcation. Furthermore, lane-tracking behavior for participants exposed to roundabouts with pavement markings was similar to lane-tracking behavior observed in a recent field study. Observations of speed indicated that drivers drove faster though roundabouts with a large central island radius as opposed to a roundabout with a smaller central island radiu