By default I take a devil's advocate stance to public hype, so I hope I don't come off as too negative by saying this is incredibly impractical and inefficient. The issue with solar isn't that we don't have enough panels, or places to put panels, it's that it's not energy dense and takes a very long time to pay for itself. Add in factors such as inclement weather, the necessity to face the sun, and the prohibitive cost to maintain such expensive equipment over vast stretches of road, and you've got a really absurd premise. I'd much rather see a bigger use of solar panel roofing, and efforts to make them less expensive so they're available to anyone.