Can't believe no one has mentioned this yet.

https://www.indiegogo.com/projects/solar-roadways

I'm excited to see what their numbers are. I have a hunch this will be über expensive…but I'd think for state highways in the middle of nowhere southern united states, that a ton of energy could be created.

I think these would be super ineffective on streets, especially ones running N/S in big cities, but for cemented areas in parks, it would be a fantastic feature, considering it's more than just a way to harness energy. Parking lots in less developed areas would surely find this to be a good long-term investment.