Public transportation agencies can certainly be inflexible. Frank Martz, the city manager of Altamonte Springs, Fla., envisioned a service in the late 1990s that was basically Uber before smartphones. He wanted to allow riders to use computers or kiosks to order smaller vehicles with optimized routes. The local transit agency struggled to bring his idea to life.

“They just could not think about anything other than buses and bus lanes, and drivers and unions,” Mr. Martz said. “They could not think about the user.”

This month, Altamonte Springs finished a two-year pilot offering discounts on Uber rides instead, a model that appeals to the belief that private companies can provide these services better anyway.

“I expect by 2030, most transit agencies are going to be zombie agencies that exist mainly to collect taxes from people to pay down their debt,” said Randal O’Toole, a senior fellow with the libertarian Cato Institute who blogs, provocatively, as “The Antiplanner.” In the meantime, he argues that cities should put no new money into infrastructure.

He acknowledged that he believed transit was wasteful for taxpayers long before everyone got excited about driverless cars. But now he and others who say no to transit also have something positive to say. Something better is coming.

Las Vegas Isn’t in a Gambling Mood

Las Vegas has been preparing to build precisely the thing these critics say they shouldn’t: the region’s first light rail line. The city is running several autonomous pilots, too, but officials aren’t sold on the imminent driverless future.

“It’s very easy to get caught up in these sensationalized visions,” said Tina Quigley, general manager of the Regional Transportation Commission of Southern Nevada. “Some of these visions may eventually come to fruition. But we are not talking about them happening in the next five years even, some of them in the next 10 years.”