For a track it could be something like a long metal plate embedded in the road that you drive over with a parallel long metal plate suspended above the track; o

For a track it could be something like a long metal plate embedded in the road that you drive over with a parallel long metal plate suspended above the track; one side is positively charged and the other side is negative. Since all the cars are basically the same size, the "pantograph" might only stick up a few inches. A somewhat more complex system might have power and ground rails embedded in slots in the road surface, and there's something on the bottom of the car that drops a conductor into the slots. There's a test of that kind of system being done in Norway or Sweden (I forget which) on a public road.