Evaluation of forward collision warning system for urban driving

Commercially available forward collision warning systems (FCWS) have been designed for highway use, with traffic moving in regular patterns on roadways with modest curvature. The development and the evaluation of an FCWS for urban driving are described. An urban FCWS is significantly more complicated because of irregular movements of subject (equipped) and target vehicles, as well as the presence of many static objects close to the vehicle's path (parked cars, street furniture, etc.). The prototype FCWS was tested for 1 year on two urban transit buses in public service in San Mateo County, California, and Pittsburgh, Pennsylvania. Analysis of the data collected from these tests shows that the FCWS produced favorable changes in driving behavior, generally leading bus operators to drive more cautiously and consistently. The tests did not continue long enough to determine long-term changes in driving behavior or carryover effects after FCWS use ended, so additional testing is needed to address those issues.