Any level of distraction can worsen reaction time in case a driver sitting behind the wheel of an autonomous vehicle needs to take control, especially if the driver is relatively inexperienced, a recent study finds.
As vehicles are capable of greater and greater levels of automation, their drivers are currently allowed to engage in tasks not related to driving. Still, they are generally at times expected to seize control over the vehicle in situations the automated system cannot handle.
Many anecdotes show drivers in autonomous vehicles are not capable of properly taking over a vehicle if necessary. Scientists wanted to see what factors might play a role in how well or poorly drivers performed in such emergencies, such as what might be distracting them or how experienced they were at driving.
In the new study, researchers tested volunteers in a driving simulator of a vehicle capable of SAE level 3 automation, which requires a human driver to take control if the system demands. The scientists focused on volunteer speed and effectiveness in taking control of the vehicle in the event of an emergency.
The researchers had 19 volunteers write business emails to simulate working while driving, watching videos on social media to simulate getting entertained, and taking a break with their eyes closed to simulate resting.
“These tasks required drivers to invest high, moderate, and low levels of mental workload,” study lead author Neng Zhang at the Royal Melbourne Institute of Technology in Australia said in a statement. “We tested their responses after a short interval, 5 minutes, or long interval, 30 minutes, of participating in one of these tasks.”
All of the tasks worsened how well the volunteers took over the vehicles and led to a period of poorer driving.
“We found that resting resulted in the worst takeover response, followed by working,” Zhang said in a statement. “Social media was less disruptive. However, the longer the participant engaged in an activity, the worse their response was to an emergency.”
Emergencies require a high level of thought, warned study co-author Stephen Robinson at the Royal Melbourne Institute of Technology.
“As soon as something unexpected happens, such as a child running across the road, we need to be able to use our full cognitive abilities to assess the situation and take appropriate action,” Robinson said in a statement. “Takeover requests in automated vehicles occur when the onboard computer lacks the capacity to deal with changed or complex driving conditions. Such conditions are potentially dangerous and require the driver to focus quickly and act decisively to keep our roads safe.”
The scientists also looked at how much experience played a role in performance. They found that relatively inexperienced drivers — those with less than 20,000 kilometers of driving experience, responded more slowly and less effectively. “The distance driven since gaining a driver’s license is more important than the number of years since the license was issued,” Zhang said in a statement.
The researchers said these findings highlight the need for manufacturers and regulatory agencies to develop solutions to make sure that automated vehicles are safe for drivers with varying experience levels. They are now investigating how to stimulate alertness in order to reduce distraction, as well as to improve the effectiveness of driver takeovers.
“The aim of our work is to enhance ‘human-automation interaction’ for autonomous vehicles and significantly improve the way humans interact with and control these advanced autonomous vehicles, leading to enhanced efficiency and safety in their operation,” study co-author Mohammad Fard at the Royal Melbourne Institute of Technology said in a statement.
The scientists detailed their findings in the Journal of Safety Research.