A new study by the Insurance Institute for Highway Safety and MIT’s AgeLab indicates that drivers may become dependent upon partially-automated driving systems. As they become familiar with the automation, they may be more willing to engage in distracting activities or otherwise rely on the technology to drive the vehicle.
Currently, there are no fully self-driving systems available in production vehicles. The two partially-automated systems tested in the study, adaptive cruise control (ACC) and Pilot Assist, are not designed to replace drivers. In fact, these systems routinely run into trouble negotiating the roads and a number of high-profile accidents have been reported.
Drivers must remain in full control of their vehicles at all times. They must be ready to take over for the partial automation system at a moment’s notice. However, it is easy to forget that, especially after using the systems for a period of time without incident.
“This study supports our call for more robust ways of ensuring the driver is looking at the road and ready to take the wheel when using Level 2 systems,” says the study’s lead author, a senior research scientist at the Insurance Institute for Highway Safety. “It shows some drivers may be getting lulled into a false sense of security over time.”
Volunteers tested the Land Rover Range Rover Evoque and the Volvo S90
The Evoque offers ACC, which keeps the vehicle at a chosen speed while maintaining a pre-established following distance. The Volvo S90 offers both ACC and Pilot Assist, which adds lane-centering technology to the ACC.
Volunteers allowed the researchers to record data while they tested the two vehicles over a period of time.
At first, there appeared to be no difference in the level of driver engagement between driving manually and using either ACC or Pilot Assist. However, after a month drivers were substantially more likely to take their hands off of the wheel or otherwise disengage when using the partially-automated systems. The effect was more pronounced on the drivers using Pilot Assist.
“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,” says the lead author of the study. “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.”
The Volvo S90 drivers were less likely to become disengaged when they used only ACC and not lane-centering. However, only 40% of the subjects used ACC alone after they became familiar with the full Pilot Assist capability.
Even the drivers of the Evoque were more likely to answer a cellphone call when using ACC than when driving manually. This was true despite the fact that ACC does not fully take over driving like the Pilot Assist appears to. However, the Evoque drivers using ACC were no more likely than manual drivers to engage in texting or other cellphone manipulation. And, unlike the S90 drivers, the Evoque drivers were not any more likely to take both hands off the wheel when using ACC.
The addition of lane-centering may not improve safety
Field research has suggested that vehicles with ACC could be safer even than those offering forward collision warnings and automatic emergency braking. This could be because ACC controls your speed and following distance.
However, there is currently no data suggesting that adding lane-centering technology enhances a vehicle’s overall safety.
Partial automation cannot replace a driver’s dedicated attention. According to the researchers, driver disengagement has been a major factor in all known fatalities involving a car with a partial automation system.
If you think your safety features can excuse you from paying close attention to the road, think again.