bionicjoey , 7 months ago

Metal roads. But since metal is expensive you probably want just two strips of it under the wheels. And since it will wear away at the rubber you probably would want the cars to have metal wheels as well. And at that point you could make the wheels form around the rails in order to make it easier to move fast without sliding. And then you could make the cars a lot bigger and link them together and have one big car push a whole bunch of them.