Effects of Driver Behavior on Traffic Flow at Three-lane Roundabouts

This paper proposes Multi-stream Minimum Acceptable Space (MMAS) Cellular Automata (CA) models to simulate driver behavior and its effects on traffic flow at three-lane roundabouts. Using cellular automata, the models are developed by modeling the detailed space considerations for drivers entering un-signalized threelane roundabouts. Heterogeneity and inconsistency of driver behavior and interactions at entrances of three-lane roundabouts are simulated by incorporation of different categories of driver behavior and reassignment of categories with given probabilities at each time step. The models are able to reproduce many features of traffic flow at roundabouts for which gap-acceptance models are less appropriate. Various properties of traffic flow at three-lane roundabouts have been explored including throughput, turning rates, critical arrival rates and congestion on roundabouts. Vehicle movements in this paper relate to left-side driving, such as in Australia, New Zealand and Ireland. However, rules are generally applicable.