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…