SIMULATION OF HIGHWAY TRAFFIC

Through the combination of several specialized traffic models founded on kinematic wave theory a more general macroscopic simulation model has been developed. The model may handle traffic systems which consist of highways with up to two lanes in one direction, traffic lights (not at intersections) and ramps. The parameters may be combined in any way desired and the model has been programmed in a language called SIMULA 67. The model has been used to simulate traffic conditions on a four lane motorway (two lanes in each direction). A 5 km stretch with on-and-off-ramps was tested with regard to imbalance of capacity and demand at various segments of the system. Flow conditions and queue build-ups both on the main line and on the ramps were simulated as well as queue dispersal. Some of the results are presented in graphs. The model may in general be used to investigate what influence changes in geometrics or traffic control may have on the operational characteristics of a highway or highway system. The results may be presented in graphs showing shock waves, queue build-ups, speed and capacity reduction as result of congestion. It may handle several km of highway and thousands of vehicles at any one time. (Author/TRRL)