Evaluation of incident management benefits using traffic simulation

The impacts of Intelligent Transport Systems (ITS) on network performance can be evaluated either in field studies or using traffic simulation. Field studies are generally expensive to complete and they donít offer any flexibility in investigating alternative scenarios. The use of computer modelling, and microscopic traffic simulation in particular, offers a better and more cost-effective approach, in which the modeller can vary the input conditions and measure their impacts on network performance. This paper presents results from a simulation approach developed to evaluate the impacts of Incident Management (IM) programs. These programs are aimed at reducing the impacts of incidents, which account for 50-60 percent of total delays on US freeways (Lindley, 1987), by using automated incident detection techniques (e.g. Dia and Rose, 1997); verifying and classifying the nature of incident; notifying emergency services; clearing the incident and restoring traffic conditions in the shortest possible time. It is clear that the benefits of these programs will depend on the extent of existing congestion in the road network, and will also vary according to the severity of the incident, its duration, and the time of day during which the incident occurs