I have more than 100 entries now. Which is awesome, but I'm sure you wanted me to come up with some sort of insane invention.
Fine. I propose a highway consisting of uncountably many little conveyor belts, thereby distributing the energy needs of propulsion between the car and the city power grid.
What's that, the tires might get caught in between the belts? Or the belt would have to be implausibly long? And getting on the offramp would involve an abrupt deceleration of the speed of the belt?
If this seems like a bad idea, it's because I thought of it when I was ten and had studied neither mechanics nor physics yet.