This article describes the VISSIM simulation system, recently developed in Germany to enhance the development of optimal traffic signal settings. VISSIM can be used in conjunction with traffic controllers using the Swiss VS-PLUS system, which has several remarkable features. VISSIM is a general-purpose computer-based stochastic traffic simulation system, which models links, roundabouts, priority junctions, signal-controlled intersections, and road networks in great detail. It combines measurements of traffic by detectors with a sophisticated traffic flow model. It enables: (1) single vehicle modelling; (2) online animation of traffic flows; and (3) offline reports of travel times and delays. The simulation model and the control strategy are two separate modules. VISSIM can model other phase- and stage-based control strategies without much effort. It is a master program, which sends second-by-second detector values to the (slave) signal control program, which uses the detector values to decide the current signal aspects. VISSIM receives these aspects, and starts the next iteration of traffic-flow starts. VISSIM has been a valuable traffic control tool in several German cities and in Basel, Switzerland and Dublin, Ireland.
Abstract