INSECT - The Calibration and Validation of an Intersection Simulation Model

This paper presents the calibration and validation of the INSECT model. INSECT is a vehicle by vehicle intersection simulation model for dealing with sign controlled intersections, roundabouts and more recently traffic signals. This paper covers the validation of non-signalised intersections. The calibration and validation indicated that the model gave good results across the whole range of intersections tested. The work has indicated that fixed gap times are not applicable either to individual intersection types or within intersection types. This is mainly due to the fact that there are different gap acceptance characteristics between sign controlled intersections and roundabouts. Also, that the gap accepted by the motorist is related to the time that they have waited. It is believed that INSECT is a useful tool for the evaluation of all types of intersections and it has recently been extended to cover traffic signals which will be the subject of a future paper. In addition, it is intended to extend the INSECT model to the accident prediction area where the number of conflicts can be determined automatically and the model used as a surrogate survey tool.