Analysis of Braking and Steering Performance in Car- Following Scenarios

This paper presents recent results of on-going research to build new maps of driver performance in car-following situations. The novel performance map is comprised of four driving states: low risk, conflict, near crash, and crash imminent – which correspond to advisory warning, crash imminent warning, and crash mitigation countermeasures. The paper addresses two questions dealing with the approach to quantify the boundaries between the driving states: (1) Do the quantified boundaries strongly depend on the dynamic scenario encountered in the driving environment? and (2) Do the quantified boundaries vary between steering and braking driver responses? Specifically, braking and steering driver performances are examined in two car-following scenarios: lead vehicle stopped and lead vehicle moving at lower constant speed. The analysis was conducted on experimental data collected from test track studies to develop a fundamental understanding of drivers’ lastsecond braking and steering performance. The results of last-second braking performance analysis showed that the quantified boundaries depend on the dynamic scenario. On the other hand, the quantified boundaries were independent of the specific dynamic scenario based on the analysis of last-second steering performance. Finally, the quantified boundaries varied between braking and steering responses since drivers initiated last-second braking maneuvers at generally longer distances than last-second steering maneuvers.