Effects of Bottlenecks on Vehicle Traffic

Traffic congestion is usually observed at the upper stream of bottlenecks such as tunnels. Congestion appears as stop-and-go waves and high-density uniform flow. We perform simulations of traffic flow with a bottleneck using the coupled map optimal velocity model. The bottleneck is expressed as a road segment with speed reduction. The speed reduction in the bottleneck controls the emergence of stop-and-go waves. A phenomenological theory of bottleneck effects is constructed.