More Self-Driving Cars = More Miles Driven & More Energy Consumed

A study by researchers at the University of Michigan School For Environment And Sustainability led by doctoral fellow Morteza Taiebat claims people with self-driving cars will drive more miles, which in turn means the transportation sector will use more energy rather than less.

“The core message of the paper is that the induced travel of self-driving cars presents a stiff challenge to policy goals for reductions in energy use,” said co-author Samuel Stolper, assistant professor of environment and sustainability at SEAS. Co-author Ming Xu adds, “Thus, much higher energy efficiency targets are required for self-driving cars.”

Economic theory posits that everything we do means we can’t be doing something else. If you are hang gliding in the Alps, for instance, you cannot be attending classes at the University of Michigan at the same time. But self-driving cars open up a whole new chapter in human endeavor. Now you can be driving and writing your doctoral thesis simultaneously.

The researchers suggest this ability to multi-task will create a 38% reduction in perceived travel time cost, resulting in what they call “induced travel” — driving more often and over longer distances while watching videos, taking selfies every quarter mile, tweeting, and doing other socially inappropriate things while our cars transport us serenely along life’s highways and byways. “What a wonderful world it will be. What a glorious time to be free,” as Donald Fagen might put it.

The result? “Backfire — a net rise in energy consumption — is a distinct possibility if we don’t develop better efficiencies, policies and applications,” Taiebat says, according to a report by Science Daily. The possibility of such a backfire implies the possibility of net increases in local and global air pollution, the study authors conclude.

In addition, the researchers suggest there’s an equity issue that needs to be addressed as autonomous vehicles become a reality. The study finds that wealthier households are more likely to drive extra miles in autonomous vehicles “and thus stand to experience greater welfare gains.” By “welfare,” they don’t mean collecting payments from the government; they mean enjoying advantages not available to people of lesser economic means.

Say what you will about the social and political overtones of the study, the point is that if people no longer need to take time out from their busy lives to actually drive their cars, they will feel more comfortable using those cars more. If we expect self-driving cars to lower total fuel consumption — whether of molecules or electrons — this study suggests we may be disappointed.