Self-driving cars are coming. Whether it's Tesla's Model 3 or Uber's automated ride-hailing service, many cities will probably start seeing these vehicles on the road in just a few years.

But some may not be ready for the change. How cities maintain their roads, train their workers, design their institutions and even plan their use of land might need to change dramatically as vehicle automation becomes more widespread. So to help give them a jump-start, former New York mayor Michael Bloomberg wants to develop a set of policy recommendations for cities that are just waking up to the driverless revolution.

Five cities will serve as testing grounds and early participants in the conversation: Austin, Los Angeles and Nashville in the United States, as well as Buenos Aires and Paris. Five additional cities will be named by year's end.

"The advent of autonomous cars is one of the most exciting developments ever to happen to cities," Bloomberg said. "And if mayors collaborate with one another, and with partners in the private sector, they can improve people’s lives in ways we can only imagine today."

It's hard to say what these recommended policies will look like; Bloomberg's philanthropic arm and the Aspen Institute want to start by getting mayors, academics and other experts talking and planning for the future. Much of the focus appears to be on social, environmental and economic welfare.

"This is a once-in-a-generation opportunity for cities to address some of their most challenging issues, from pedestrian safety to carbon reduction to economic mobility," said James Anderson, who leads the government innovation program at Bloomberg Philanthropies.

Automation is poised to transform the labor economy as some workers are replaced by robots. Dense urban centers are likely to be served by roving driverless cars that work for ride-hailing services. And smarter vehicles that can communicate with one another may lead to reductions in congestion and car crashes.

All of these changes should get urban planners thinking about how to serve city residents better, said Raj Chetty, an economics professor at Stanford University. Driverless cars, he added, could help connect low-income people to places they cannot access by public transit. At the same time, driverless cars could simply contribute to sprawl by allowing wealthy people to live in ever more distant suburbs.

"Ensuring that a shift to driverless cars increases opportunity and improves the lives of urban residents across the world will require carefully designed social and economic policies," he said.