Researchers from Stanford University have concluded that drivers who retake control of an autonomous car are more likely to be involved in an accident.
The study, published in the first issue of Science Robotics, found that roads could become especially dangerous when drivers made the transition back to being in control of autonomous vehicles due to changes in speed and other changes in driving conditions.
“Many people have been doing research on paying attention and situation awareness. That’s very important,” said lead author of the research and former graduate student in the Dynamic Design Lab at Stanford University, Holly Russell.
“But, in addition, there is this physical change and we need to acknowledge that people’s performance might not be at its peak if they haven’t actively been participating in the driving.”
During testing all drivers were given advance warning that they would be put back in control of a driverless car and were given the opportunity to drive around the testing track a number of times, so they could feel for themselves changes in speed or steering that may occur while the car drives itself.
However, during the trial itself, the drivers’ steering manoeuvres differed significantly from their ability when in control of the car from start to finish.
“Even knowing about the change, being able to make a plan and do some explicit motor planning for how to compensate, you still saw a very different steering behaviour and compromised performance,” said co-author of the research and research associate in the Revs Program at Stanford, Lene Harbott.
Although no driver was so thrown off by the changes in steering that they drove off-course, the fact that there was a period of altered steering behaviour increased the likelihood of an accident occurring.
However, the Stanford study only addressed one specific example of the autonomous car to human driver handover; there is still a lot to learn about how people respond in other circumstances, depending on the type of car, the driver and how the driving conditions have changed.
“If someone is designing a method for automated vehicle handover, there will need to be detailed research on that specific method,” said Harbott. “This study is tip of an iceberg.”