Data requirements and sources for the calibration of microscopic motorway simulation models

At higher levels of demand, the flow of traffic on motorways can become unstable with flow breakdowns and an increase in accident risk. Improvements in capacity and stability may be achieved by modifying behaviour or control, and this process is the target of research into preventative IVHS measures. However, to understand the effects it is necessary to develop and use appropriate microscopic simulation models. To calibrate a microscopic simulation model, a large amount of checking should be performed to ensure that the model behaves correctly, at both a microscopic and a macroscopic scale. This procedure is not straightforward as microscopic data is complex to obtain and interpret, due to the diversity of the information required, and because many parameters used in model formulation are not directly related to easily observable quantities