With the rise of autonomous vehicles, it’s tempting to think that we can sit back and enjoy a comfortable and relaxing ride.  Alas, a couple of recent studies suggest that isn’t actually the case.  For instance, one study, which I covered recently, suggests that traveling in a driverless car is actually pretty tiring.

It found that people tend to tire much faster in autonomous vehicles than they do in regular cars, with the fatigue especially rapid if they are already tired to begin with.

A similar finding emerged from a second study undertaken by researchers at Texas Tech University.  As with the previous study, much of the tiredness is due to the need to keep constant vigilance in case we need to regain control of the vehicle.

“State-of-the-art vehicle automation systems are designed to safely maintain lane position, speed, and headway without the need for manual driving. However, there are some situations in which the automation system may fail without warning. To compensate for this, drivers are expected to remain vigilant, continuously monitor the roadway, and retake control of their vehicle should the need arise, but past research has shown that a person’s ability to remain vigilant declines as a function of time,” the researchers say.

Alert at the wheel

Volunteers were placed inside a driving simulator whereby the vehicle was controlling itself for 40 minutes.  They were tasked with observing other vehicles that were stopped at intersections and identifying those that were positioned unsafely.  When they spotted such a hazard, they were required to press a button.

The proficiency of the volunteers declined significantly as the task progressed, with 30% fewer hazards identified at the end than at the beginning.  What’s more, reaction times also declined significantly.  When quizzed afterwards, the volunteers reported finding the task both difficult and stressful.

“Our results demonstrate that there are high costs associated with the need for sustained supervisory duty in automated vehicles,” the authors say. “And the expectation that a human driver will provide reliable, attentive oversight during vehicle automation is untenable. Monitoring for automation failures can be quite demanding and stressful, suggesting that vehicle automation does not ensure an easy or carefree driving experience. As a result, vigilance should be a focal safety concern in the development of vehicle automation.”