Visions of an autonomous car future may come with a few bumps. UCLA Luskin’s Adam Millard-Ball, professor of urban planning and director of the UCLA Institute of Transportation Studies, commented in a Wired story on how a so-called robotaxi revolution could play out as self-driving vehicles are hitting the road. Promoters of a driverless future like Tesla’s Elon Musk see a promising outlook for autonomous taxis, including car sharing systems that allow self-driving-car owners to rent out their vehicles while not in use by the owner, potentially alleviating parking problems. Not exactly, say some experts like Millard-Ball, citing studies of Uber and Lyft’s effects on U.S. cities that show the introduction of these services have actually created more urban traffic. “That’s going backward for the environment and for other urban goals — whether it’s being physically active or socially inclusive,” Millard-Ball said.