The validation of a microscopic model for the simulation of traffic and traffic control.

In traffic and transportation research all kinds of models are used to make predictions about the behaviour of traffic. But the question of the validity of models is often not put nor answered. FLEXSYT-II- is a microscopic traffic simulation model, used in and outside The Netherlands to study all kinds of traffic management measures including traffic control in cities. Recently, this model was validated. Simulation results were compared with real-life measurements. For FLEXSYT-II- three situations were analysed: a single intersection, a roundabout and an arterial consisting of three intersections. The results were promising. For all situations the model showed a good resemblance in results and an improvement in comparison with a previous validation. Still, some work needs to be done to refine the model and to make it work even better. The main conclusion is that validating a model is a difficult and time consuming process which is often underestimated, but is necessary to make reliable predictions about the effects of traffic control and other measures. For the covering abstract see IRRD E102946.