Why? Self-driving cars can already do those dozen blocks in Manhattan. And a lot more than that. The wait currently is to ensure every reasonable edge case is

Why? Self-driving cars can already do those dozen blocks in Manhattan. And a lot more than that. The wait currently is to ensure every reasonable edge case is handled, and to understand the degree of safety. And how does a wire in the road help avoiding pedestrians, bad human drivers, construction, etc? You still have to build intelligence into the car.