speaking of half-bakery
one thing that did come to mind was a 2d array of coils in the road, and a big permanent magnet on the underside of the nose of the "car" and some big arse coil controller that can sense the cars position, and the car tells the controller where it want to go with a low power wireless signal. The controller then turns on the right sequence of coils to take you there...
The controller can probably accommodate accounting too
