A simulation evaluation of a real-time traffic information system using probe vehicles

For probe vehicles to be the basis of a real-time traffic monitoring system, it is necessary that the travel-time measurements made by them be reliable, adequate and timely. One of the objectives of this feasibility study is to estimate the number of probe vehicles required for various types of road networks. Traffic simulation modeling analysis was used for determining probe-vehicle penetration required for different traffic conditions and different road networks (i.e., Troy, Detroit, and Grand Rapids) with a given set of system parameters. It is clear from the simulation results that the use of vehicles as probes is an attractive option for collecting real-time information in heavily traveled corridors (such as freeways) for probe penetration over 3%, during specific periods such as the peak hour. However, surface roads require considerably more than 5% penetration and need more study.