Largest Automatic Emergency Braking Study Finds Systems Improving Over Time

January 27, 2025 at 09:00 AM EST

Front-to-Rear Crashes Reduced up to 52% in Newer Models

Automatic emergency braking (AEB) continues to improve as it cuts rear-end crashes in half, according to the latest study by the Partnership for Analytics Research in Traffic Safety (PARTS). The study, pairing auto manufacturer equipment with police crash report data covering 98 million vehicles and 21.2 million crashes, is the largest and most comprehensive study of advanced driver assistance systems (ADAS) to date.

The PARTS study is a follow-up to a previous ADAS effectiveness study released in 2022. The study more than doubled the number of vehicle models included, and added three additional vehicle segments, three additional states, and three new model years. For the first time, the study included data from new PARTS members Ford and Hyundai. Other manufacturers that contributed data to this study were General Motors, Honda, Mazda, Mitsubishi, Stellantis, Subaru, and Toyota.

The data showed an increase in AEB effectiveness, from 46% across model years 2015–2017 to 52% across model years 2021–2023, indicating that advancements in the technology have led to tangible improvements.

The PARTS data also showed a 9% reduction in single-vehicle frontal crashes with non-motorists, including pedestrians, cyclists, scooters, and wheelchairs, for vehicles equipped with pedestrian automatic emergency braking (PAEB) systems. This is the first time a statistically significant measure of PAEB effectiveness has been quantified by PARTS. Pedestrian crashes are among the most severe forms of traffic crashes, with deaths accounting for 18% of all traffic fatalities, according to NHTSA.

PARTS is a partnership between automobile manufacturers and the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) and operated by MITRE.

“The size, growth, and iterative nature of this study are incredible,” said Jennifer Morrison, PARTS communications chair and head of vehicle safety for Mazda North American Operations. “The industry has voluntarily developed and deployed these crash avoidance systems. We can now see a trend in their life-saving capabilities and can focus our efforts on continuing that trend.”

The data will be used to further study ADAS effectiveness in reducing crash severity. Future studies will incorporate data from Kia, the newest PARTS member. The effectiveness study considered whether a vehicle was equipped with a given ADAS feature at the time of manufacture, and future studies will attempt to assess whether that feature was on or activated at the time of crash.

“PARTS continues to provide crucial insights into improving vehicle safety, and MITRE is proud to work alongside NHTSA and automakers in this collaborative partnership,” said Kerry Buckley, vice president of MITRE’s Center for Integrated Transportation. “PARTS will continue to provide real-world insights into the safety benefits and opportunities of emerging advanced driver assistance systems.”

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