A Model for City Traffic

Summary

We propose a simple cellular automaton to simulate city traffic. Vehicles on road are treated as particles hopping on a lattice. In the morning rush hours, downtown parking lots are taken as the sinks for vehicles moving from suburban; in the afternoon rush hours, the parking lots become the sources for vehicles moving out of town. The traffic is regulated by the operation of a series of traffic lights on each street block. Both the traffic flow (from global perspective) and the travel time (from personal perspective) are studied. It is found that even in maintaining the same traffic flow, the tuning of traffic lights can significantly affect the travel time, and correspondingly the duration of rush hours.