As cars become more autonomous, it’s important to think about how drivers will respond. Even though there are no fully automated vehicles on the road yet, some drivers are already relying on driver assist systems and taking their hands off the wheel.
This has resulted in a number of tragedies. Whenever a semi-autonomous vehicle is involved in a fatal collision, crash investigators seek to discover why. In virtually every case, driver disengagement has been a major factor. In other words, the driver took their eyes off the road or their hands off the wheel and allowed the car to do the driving.
That’s dangerous. None of the driver assist systems available today are capable of fully self-driving. All of the manuals explain that every driver must be fully engaged and ready to take over at a moment’s notice. Yet, with names like the Tesla Autopilot, some drivers are apt to be confused.
Many people are prone to believe that semi-autonomous vehicles are fully self-driving and can be used without much input from the driver. There is another problem, though, revealed in a recent study by the Insurance Institute for Highway Safety (IIHS). Even when there is no question that the system is only semi-autonomous, drivers may come to rely on the technology and allow themselves to become distracted.
Do semi-autonomous driving systems actually increase our safety?
The IIHS asked 20 drivers to drive one of two types of vehicles with semi-autonomous technology. Half drove the Land Rover Range Rover Evoque, which has adaptive cruise control, or ACC. ACC maintains your speed and a safe following distance so all you have to do is steer.
The other half drove a Volvo S90, which has both ACC and Pilot Assist, a lane-centering device. The lane-centering technology keeps the vehicle positioned within the lane of travel, eliminating even the need to steer.
When the volunteers first began driving the vehicles, their driving engagement didn’t change. Whether they were driving manually or using the ACC or ACC with lane assist, they continued to drive carefully. But after a month or so of using the semi-autonomous features, this began to change.
After becoming familiar with the controls, the drivers were substantially more likely to take their hands off the wheel or otherwise let their focus wander when using the semi-autonomous systems. The effect was more pronounced among the Volvo S90 drivers, whose vehicles had greater automation.
“Drivers were more than twice as likely to show signs of disengagement after a month of using Pilot Assist compared with the beginning of the study,” explains the study’s lead author. “Compared with driving manually, they were more than 12 times as likely to take both hands off the wheel after they’d gotten used to how the lane centering worked.”
Even the Evoque drivers, who only had ACC, were more likely to pick up cellphone calls when using the technology than they were when driving manually. However, they were no more likely to text or manipulate their cellphones, and no more likely to take both hands off the wheel.
The drivers apparently got lulled into a false sense of security as their familiarity with the cars’ capabilities increased.
Partial driving automation technology holds the promise of reducing crashes caused by driver error. However, they are not ready to take over for drivers. Every driver needs to be alert, sober and ready to take over in case the technology fails unexpectedly.