Partial automated driving systems, such as those that assist with steering on highways, have not significantly improved road safety, according to a recent study by the Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI). This contrasts with other advanced driver assistance systems (ADAS), which have been shown to reduce crash and claim rates significantly.
Findings of the Study
David Harkey, IIHS president, remarked, “Everything we’re seeing tells us that partial automation is a convenience feature like power windows or heated seats rather than a safety technology.”
The study focused on two older partially automated driving systems: model-year 2017–2019 Nissan Rogues with ProPilot Assist and model-year 2013–2017 BMWs with Driving Assistant Plus. These findings follow earlier studies from 2021 that highlighted the benefits of certain ADAS features.
Performance of ADAS in Older Models
BMW’s collision avoidance systems, for example, have reduced claim frequencies for various types of vehicle damage, property liability, and injury claims. However, when analyzing crash rate data, IIHS’s senior vice president of research, Jessica Cicchino, found no significant difference in lane departure crashes between BMWs equipped with lane departure warning and prevention systems and those with both systems plus partial automation, compared to cars without any steering assist. This analysis controlled for variables such as driver age, gender, and model year.
Notably, BMWs with lane departure warning and prevention systems did have significantly fewer lane departure crashes during daylight hours than cars without such systems.
Impact of ADAS in Nissan Rogues
Nissan Rogues with ADAS features showed a significant reduction in rear-end and lane departure crash rates. The most considerable benefit was seen in Rogues equipped with partial automation, forward collision warning, automatic emergency braking, lane departure warning, and lane departure prevention, compared to those without such systems. However, these benefits were primarily observed on surface streets and roads with speed limits below 35 mph, where ProPilot Assist does not function unless following another vehicle. This suggests other factors, such as better-equipped headlights, may be at play.
Challenges in Evaluating Lane-Keeping Systems
Determining the safety impact of lane-keeping systems is challenging. Unlike constant-monitoring crash-avoidance systems, lane-keeping systems require active engagement by the driver, which is not always consistent. Studies that use telematics data from cars, recording when these systems are activated, could provide more accurate insights.
Jessica Cicchino emphasized, “With no clear evidence that partial automation is preventing crashes, users and regulators alike should not confuse it for a safety feature. At a minimum, safeguards like those IIHS promotes through its rating program are essential to reduce the risks that drivers will zone out or engage in other distracting activities while partial automation is switched on.”
Conclusion
While partial automated driving systems offer convenience, their contribution to road safety remains questionable. The study underscores the importance of differentiating between convenience features and true safety technologies in driver assistance systems.