Crash records and insurance data offer little evidence that partial automation systems are preventing collisions, according to new research from the Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI).

The organizations said the clearest evidence so far comes from studies of BMW and Nissan vehicles that have been on the road for a number of years. HLDI studied these vehicles in 2021. Now it says its new study of the same vehicles confirms that partial automation in these vehicles does not confer additional safety benefits beyond those of crash avoidance features like front automatic emergency braking (AEB).

“Everything we’re seeing tells us that partial automation is a convenience feature like power windows or heated seats rather than a safety technology,” said IIHS President David Harkey.

In the studies of BMW and Nissan, HLDI found that property damage liability claims — which are for damage to other vehicles hit by the insured driver — were eight per cent lower for 2017-19 Nissan Rogues equipped with forward collision warning and AEB. However, there was no additional benefit associated with adaptive cruise cruise control (ACC) or Nissan’s ProPILOT Assist partial automation system, which adds lane centering on top of ACC.

Similarly, forward collision warning and AEB were associated with a seven per cent reduction in collision claim rates and a 13 per cent reduction in property damage liability claim rates for 2013-17 BMW and Mini vehicles.

BMWs and Minis that were also equipped with ACC showed a larger, 25 per cent reduction in property damage claims and no greater change in collision claims. As with the Nissan vehicles, there were no additional statistically significant reductions associated with BMW’s Driving Assistant Plus partial automation system.

“With no clear evidence that partial automation is preventing crashes, users and regulators alike should not confuse it for a safety feature,” said Jessica Cicchino, senior vice president for research at IIHS.

“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.”