Has Robocar Safety Been Hyped?

Autonomous cars may never be as safe as the best human drivers, says a new report

Illustration: Harry Campbell

A study out today throws cold water on the accident-free paradise that proponents of autonomous cars have prophecied. 

Not only may robocars never be as safe as the best drivers, their growing pains may temporarily lower overall road safety, say Michael Sivak and Brandon Schoettle, psychologists at the University of Michigan’s Transportation Research Institute. 

They note that some accidents will still be caused when human beings make mistakes for which robotic cars cannot compensate. If, for example, a child darts in front of a car from out of nowhere, even instantaneous braking may not stop the car in time.

Nor is it a foregone conclusion that the strengths of autonomous cars will outweigh those of good drivers.  True, autonomous cars never tire or get distracted, and they can respond to new information almost immediately, but these factors wouldn’t necessarily  “trump the predictive experience of middle-aged drivers.”

Middle age is the sweet spot for safety, because by that stage in life drivers are less likely to take risks and knowledgeable enough to intuit what other people are likely to do. 

Then there is the problem of system failures, which, even in today’s human-piloted cars, cause about 1 percent of fatal accidents. The researchers say that some failures—like a burned-out light—might not bother a self-driving car, which has many overlapping sensor systems. But other kinds of failures may become more common, because the sensing and information-processing hardware is so complex.

Of course, the researchers are trying to correct what they regard as excessive technological optimism. Still, is it entirely fair of them to compare robocars only to the best drivers? Most accidents are caused by the worst ones, and it is beginning to become clear that those are the people that a robot could outperform with one clanky arm tied behind its back.

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