Cellular Automata Simulation of Traffic Jam in Sag Section

A traffic congestion often occurs near a sag section on a freeway. Since a road gradient changes gradually in a sag section, a driver dose not notice it and therefore, a traffic congestion occurs. This paper describes the cellular automata simulation of the traffic flow through a sag section. The simulation is performed by the stochastic velocity model[4]. The results show that the effect of a sag zone to the traffic congestion becomes strong according to the increase of car density and that average velocity tends to decrease not at the sag section but at a little ahead point of sag section.