Has Electronic Stability Control Reduced Rollover Crashes? 2019-01-1022

Vehicle rollovers are one of the most dangerous crash modes in the US – accounting for 35% of all occupant fatalities annually. Electronic Stability Control (ESC) has been estimated to have an effectiveness of 16.7% for all non-rear-end crashes and 56.2% for all control loss crashes and thus has great promise to alleviate the rollover problem. The objectives of this research were (1) to estimate the effectiveness of ESC in preventing rollover crashes and (2) to identify cases which ESC did not prevent the rollover to prioritize advanced countermeasure development. All passenger vehicles and light trucks and vans that experienced a rollover from 2006 to 2015 in the National Automotive Sampling System Crashworthiness Database System (NASS/CDS) were analyzed. Each rollover was assigned a crash scenario based on the crash type, pre-crash maneuver, and pre-crash events. The Insurance Institute for Highway Safety ESC availability database was matched to each NASS/CDS case vehicle by the vehicle make, model, and model year. ESC effectiveness was computed using the quasi-induced exposure method. From 2006-2015, control loss accounted for 29.7% of the 1,339,407 vehicle rollovers. ESC was standard equipment in 177,644 of vehicles involved in these events. Our study estimated that ESC was effective in reducing the number of rollover crashes by 13.3%. ESC was even more effective at reducing rollover crashes due to control loss with a reduction of 50.6%. Travelling too fast for the road conditions was the most common reason rollovers due to control loss were not prevented despite the presence of ESC.