Dagim Yoseph Mengesha

Modeling Traffic Flow Problem: Comparison of Multilane Roundabout Versus Traffic Light Control Dagim Yoseph Mengesha

The vehicular traffic is controlled by a self-organized scheme in which traffic lights are absent at traffic junctions. This controlling method incorporates a yield-at-entry strategy for the vehicles approaching to the circulating traffic flow in the roundabout. Vehicular dynamics are simulated within the framework of the probabilistic cellular automata and the throughputs experienced at each individual street are evaluated for specified time intervals to determine the performance of the roundabout. We used Multi-stream Minimum Acceptable Space (MMAS) Cellular Automata (CA) model for the description of vehicular traffic at a roundabout. In this thesis inconsistency of driver behavior and interactions in cross traffic at entrances of roundabouts are simulated by incorporation of four different categories of driver behavior (i.e., conservative, moderate, urgent and radical). Our results give the critical throughput in which the intersection should be controlled in a self-organized manner is approximately 4500vph. This proves that below certain congestion, the roundabout efficiency is higher than fixed-time signalized junction point. In general, average throughputs for two-lane rounda