Not all vehicle automation systems react the same when a driver attempts to manually steer in a dangerous situation. Indeed, many drivers in systems that shut off if they use their hands to steer say they would be less likely to take over steering in potentially dangerous situations, according to a study released Tuesday by the Insurance Institute for Highway Safety.
On the other hand, among drivers in the study in vehicles with partial automation systems that allow shared control of the steering wheel, meaning the system would re-engage after manual steering, 40%-48% were less likely than the others to say they would keep their hands off the wheel in situations that would make most drivers nervous.
Senior IIHS research assistant Alexandra Mueller conducted an online survey of 1,260 owners of Ford, General Motors, Nissan/Infiniti and Tesla vehicles equipped with partial automation who regularly use the technology.
“Those are sizable differences,” said Mueller in a release. “Although there could be many reasons, one plausible explanation is that systems that switch themselves off whenever the driver steers may make drivers less likely to want to intervene, as it’s a pain to reactivate the system again and again.”
“These results suggest that small differences in system design can nudge drivers toward safer habits,” added IIHS President David Harkey, in the release.
The IIHS has been pushing automakers to equip their partial automation systems with what it terms cooperative steering which allows drivers to make minor adjustments within the travel lane without the system deactivating.
Last March, the IIHS introduced a new ratings system aimed at encouraging automakers to add more safeguards to their partial automation systems.
The organization tested partial automation systems in BMW, Ford, General Motors, Genesis, Lexus, Mercedes-Benz, Nissan, Tesla and Volvo vehicles, of which only the Teammate system available on the Lexus LS earned an acceptable rating.
“Some drivers may feel that partial automation makes long drives easier, but there is little evidence it makes driving safer,” Harkey said at the time.
In this latest study, drivers were asked to view a video used by the IIHS in developing its ratings system to determine if a system allows for cooperative steering.
In the video the driver executed a gentle maneuver to bring the vehicle from one side of the lane to the other. After watching it, the respondents were asked how their system responds when they make a similar steering adjustment.
IIHS tests confirmed conducting that maneuver manually causes both the Tesla and GM systems to stop their lane-centering support, while the Ford and Nissan systems continue to provide that support but allow the driver to dictate the vehicle’s position in the lane.
Once the Tesla system switches off, the driver must reactivate it.
The GM system can reactivate automatically, but only if the driver first returns the vehicle to the center of the lane and then stops steering, but there may be a lag before the system kicks back on.
Regardless of the system in their vehicles, many of the drivers in the study believed it stayed on after making steering adjustments, even when it didn’t.
Drivers in the study were also shown videos with three hypothetical traffic situations from the point of view of the driver in the vehicle they own.
The scenarios involving a pickup truck pulling a trailer ranged from an uneventful situation as a baseline, to one where the pickup and trailer veered in and out of the right-hand lane.
They stopped weaving by the time the point-of-view vehicle passed, although their left-side tires stayed on the lane line.
In each scenario, drivers were asked if they would place one or both of their hands on the steering wheel to move to one side of the lane.
Under the baseline, or uneventful, scenario, 36% of those with cooperative systems said they were more likely than the others to make the move.
In the third, or more hazardous situation shown in the video below, however, drivers with cooperative systems were 26% and 29% more likely than those with noncooperative systems to say they would steer to one side when passing the weaving pickup.
“These findings suggest that cooperative steering may have an implicit influence on how willing drivers are to take action when the situation calls for it, regardless of how they think their system is designed,” said Mueller.
