ABSTRACT：Forward collision warning (FCW) systems function by alerting drivers to upcoming forward hazards, and have been shown to help drivers respond more quickly under emergency situations. As FCW directly affects how vehicles interact longitudinally with one another, it may also influence car-following behavior. To investigate this effect, driving data were collected from the Shanghai Naturalistic Driving Study. Five data collecting vehicles were equipped with Mobileye® systems, which included an FCW function with headway display and warning system. Participants drove the vehicles for two months, with the Mobileye® system activated for the second month only. From the 161,055 km of naturalistic driving data collected by 60 drivers, 3,000 car-following events were selected, and the effects of FCW on car-following headway, reaction time, and parameter values of the Gazis-Herman-Rothery (GHR) model were examined. The results showed that (1) drivers tended to maintain a shorter headway with the FCW system enabled, while the proportion of time in short headways did not increase; (2) the FCW reduced car-following reaction time when the lead vehicle was accelerating and when the relative speed between the lead and following vehicle was large; (3) a reduction in the space headway exponent of the GHR model was observed when the FCW was enabled, indicating that drivers follow more closely with the FCW because the system helps them become more sensitive to the changes in following gaps. Results of this study suggest that an FCW system with a headway monitoring function may increase traffic efficiency and stability without degrading safety.
Meixin Zhu, Xuesong Wang, and Jingyun Hu. Impact on Car Following Behavior of a Forward Collision Warning System with Headway Monitoring. Transportation Research Board 98th Annual Meeting, Washington D.C., USA, 2019. 1.13-17.