Drivers’ use of front crash prevention, lane departure warning and prevention, and speed warning systems

October 2024

Introduction: Crash avoidance technologies can aid with the driving task and reduce crashes, but only if used. This study measured use of front crash prevention, lane departure (i.e., lane departure warning or prevention), and speed warning systems (i.e., systems that alert the driver when traveling above the speed limit). Methods: We observed activation rates of systems that retain their last setting with each ignition cycle on over 2,000 model year 2017 to 2023 vehicles from six manufacturers serviced at branded dealerships in the Washington, DC, metro area in 2023. We analyzed vehicle and driver demographic characteristics to identify factors associated with system use. Results: Automatic emergency braking was enabled on 93% of vehicles, ranging from 86% to 100% by manufacturer. Lane departure systems were activated on 87% of vehicles, ranging from 56% to 99% by manufacturer. Lane departure system activation rates were higher for systems that had prevention than warning only capabilities and that were activated through a settings menu versus a button. Visual speed warnings were activated on 71% of vehicles, and 14% of vehicles with an audible speed warning had the audible alert on. Conclusions: Driver use of lane departure systems has improved over time, which may be due to more lane departure prevention systems and design changes that made them more acceptable. Early use of visual speed warning alerts is strong, and we provide manufacturers and engineers suggestions of ways to improve the acceptability of audible speed warning alerts, which are effective at reducing speeding behavior.