Field Evaluation of Safety Impacts of Adaptive Cruise Control

This paper provides an attempt at evaluating the safety impacts of an Adaptive Cruise Control (ACC) system relative to Conventional Cruise Control (CCC) utilizing data that were gathered as part of a Field Operational Test (FOT) in Ann Arbor, Michigan. The safety of the ACC system is quantified considering three surrogate safety measures. The first safety measure considers the car-following behavior of an ACC system relative to manual driving in order to identify potential differences in driver/vehicle aggressiveness. The second safety measure considers changes in demands on driver resources associated with ACC technology. The third, and final safety measure, considers differences in the number of braking maneuvers and near encounters associated with ACC and CCC driving. These three surrogate safety measures are utilized to identify any potential hazards that could be associated with an ACC system. The three surrogate safety measures demonstrate consistency between ACC and manual car-following behavior, an increased usage of cruise control with adaptive features, reductions in driver manual resources and potential reductions in visual resources, and no differences in braking interventions and "near encounters." These findings collectively suggest that the use of ACC does not appear to impose a safety hazard on transportation system.