https://www.sciencedaily.com/releases/2019/01/190131125930.htm

Even worse, because cruising is less costly at lower speeds, self-driving cars will slow to a crawl as they "kill time," says transportation planner Adam Millard-Ball, an associate professor of environmental studies at the University of California, Santa Cruz.

"Parking prices are what get people out of their cars and on to public transit, but autonomous vehicles have no need to park at all. They can get around paying for parking by cruising," he said. "They will have every incentive to create havoc."