Abstract

Vision Zero, officially adopted by the US DOT in 2022, is an approach to road safety that aims to eliminate all traffic-induced fatalities and lifelong injuries. Automatic emergency braking (AEB) is an active safety system that uses forward-facing sensors to prevent and mitigate frontal crashes. Previous research has shown AEB to be a very effective system in terms of crash prevention. However, to successfully achieve Vision Zero, it is necessary to also understand the role AEB plays in injury mitigation. The purpose of this study was to estimate the future residual crash and injury population over time, assuming increasing AEB market penetration, using a frontal crash injury prediction model.


Real-word crash data was extracted from the Crash Investigation Sampling System for the striking vehicle in four AEB-applicable crash modes: rear-end crashes, left turn across path opposite direction, left turn across path lateral direction, and straight crossing paths. The 2015 Abbreviated Injury Scale was used to define occupant injury severity. First, the residual number of target population crashes over time, after AEB intervention, was estimated. The number of crashes prevented was considered to be a function of vehicle miles traveled, AEB system effectiveness, and AEB market penetration. Following the crash reduction estimate, it was estimated how many MAIS2+F injuries were mitigated due to an AEB. The probability of sustaining an MAIS2+F injury was computed using a frontal crash injury prediction model that considers maximum delta-v, occupant belt status, and occupant age. AEB-induced delta-v reduction of 34%, the computed mitigation effectiveness value was 70%.


By 2055, AEB is estimated to prevent over 3,420,000 crashes. By the same year, AEB is predicted to prevent or mitigate more than 764,000 MAIS2+F injuries. This means either the crash was prevented altogether, or the occupant will sustain an MAIS1 injury or no injury, despite the crash still happening. This study indicates AEB plays an integral role in achieving Vision Zero for the frontal crash population, and has the potential to play an even larger role if system effectiveness values increase in the future. 

 

Dean ME, Riexinger LE, “Estimating the Contributions of Automatic Emergency Braking to Achieving Vision Zero for Frontal Crashes”, 66th Annual Proceedings of the Association for the Advancement of Automotive Medicine, Student Symposium, Portland, Oregon (October 2022).