Large-Scale Analysis Using Data from 13 States Found Vehicles Equipped with Forward Collision Warning and Automatic Emergency Braking had 49 Percent Less Front-to-Rear Crashes.

Advanced Driver Assistance Systems Study Spanning Multiple US States Assessed Safety Benefits Using Crash and Vehicle Equipment Data.

Date Posted

Real-world Effectiveness of Model Year 2015–2020 Advanced Driver Assistance Systems

Summary Information

Advanced Driver Assistance Systems (ADAS) features are becoming increasingly standard on new vehicles, and their adoption is growing, owing to these systems’ potential to reduce the number and severity of traffic crashes, prevent many serious injuries, and save thousands of lives annually. The objective of this study was to explore the real-world effectiveness of ADAS in avoiding system-related crashes, using police-reported crash data and vehicle equipment data from 93 vehicle models for model years 2015 to 2020 that crashed in 13 states from January 2016 through August 2021. This study assessed the following ADAS features: Forward Collision Warning (FCW), Automatic Emergency Braking (AEB), Pedestrian Automatic Emergency Braking (PAEB), Lane Departure Warning (LDW), Lane Keeping Assistance (LKA), and Lane Centering Assistance (LCA).


In this study, vehicle data were provided by a total of eight participating industry partners, specifically leading automobile manufacturing companies, which accounted for more than 65 percent of the 2021 U.S. market for sales of passenger cars and light commercial vehicles. This study defined system-related crashes as (i) front-to-rear crashes for FCW and AEB; (ii) frontal crashes with non-motorists for PAEB; (iii) single-vehicle road-departure crashes for LDW, LKA, and LCA. This study defined three crash severity groupings and measured ADAS effectiveness for each: (i) All crashes: system-related crashes that involve property damage only, have unknown injury level, or an injury of any severity, (ii) Injury crashes: system-related crashes that involve an injury of any known severity including fatality and (iii) serious crashes: system-related crashes that involve a serious or fatal injury. This study applied quasi-induced exposure (comparing ADAS-equipped vehicles to those without such features) and logistic regression to assess the reduction in system-related crashes due to ADAS-equipped vehicles.


  • The study estimated a 49 percent reduction in all front-to-rear crashes when the striking vehicle had FCW and AEB, compared to those without either feature. In the same context, a 53 percent reduction was observed in injury front-to-rear crashes, and a 42 percent reduction in serious front-to-rear crashes.
  • The integration of warning and active braking proved more effective in reducing front-to-rear collisions than mere warnings. With only FCW, the estimated reduction for all front-to-rear crashes was 16 percent and for injury front-to-rear crashes was 19 percent. 
  • AEB performed well under all conditions, including suboptimal roadway, weather, and lighting situations. For example, AEB effectiveness diminished only from 49 percent to 42 percent in comparing daylight and dark crashes, and from 49 percent to 44 percent when comparing wet and dry road conditions.
  • The study also estimated that LDW and LKA lowered all single-vehicle road-departure crashes by eight percent and injury single-vehicle road-departure crashes by seven percent. When LCA feature was equipped, crashes decreased by 9 percent. The study did not find significant results when analyzing injury or serious crashes with these features combined, nor any notable reduction for LDW alone.
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