Effects of blind spot monitoring systems on police-reported lane-change crashes

September 2018

Objective: To examine the effectiveness of blind spot monitoring systems in preventing police-reported lane-change crashes. Methods: Poisson regression was used to compare crash involvement rates per insured vehicle year in police-reported lane-change crashes of all severities and with injuries in 26 U.S. states during 2009-2015 between vehicles with blind spot monitoring and the same vehicle models without the optional system, controlling for other factors that can affect crash risk. Results: Crash involvement rates in lane-change crashes of all severities and with injuries were 14% and 23% lower, respectively, among vehicles with blind spot monitoring than those without. Although only the reduction in crashes of all severities reached statistical significance, the effect for injury crashes was consistently in the expected direction for 5 of the 6 manufacturers examined. Discussion: Blind spot monitoring systems are effective in preventing police-reported lane-change crashes when considering crashes of all severities. If every U.S. vehicle in 2015 were equipped with blind spot monitoring that performed like the study systems, it is estimated that about 50,000 crashes and almost 16,000 injuries could have been prevented.