Determining Traffic Stream Impacts of Radar Detectors Using Microscopic Simulation

Abstract

Police radar is known to have an effect on the speed of drivers. This effect derives from the presence of vehicles equipped with radar detectors in the traffic stream and the reactions that the drivers of these vehicles have to radar. The level of impact on a traffic stream exposed to radar transmissions is a function of the proportion of radar detector equipped vehicles in the traffic stream, i.e., the radar detector density. Microscopic simulation can be used to model this impact. A microscopic simulator extension is proposed that allows determinations of this type to be carried out by adding the capability to model driver response to radar transmissions. This approach can also be applied to the modeling of other driver warning technologies such as changeable message signs. A case study using the proposed methodology to analyze different congestion and radar detector density levels is presented and discussed. The case study shows that the efficacy of using radar as a speed reduction strategy is a function of congestion and radar detector density, with the strategy being most effective for volumes levels between 200 and 1,400 vehicles per hour per lane.