After years of development and millions of dollars (including government funding), all of the solar roadways installed to date do not produce cost-effective energy production
Solar Roadways incorporated is a start-up company in Sandpoint, Idaho aiming to develop solar powered road panels to form a highway that provides energy. The plan is to replace the repaving of a road with some sort of processing that will leave it in a condition to accept hexagonal solar panels and their associated wiring and networking needs. 1
Some folks criticize the scheme since panels on roads wouldn't be tilted to follow the sun, which makes them inefficient, would often be covered by cars during periods when the sun is out, and wouldn't be capable of serving as a road for long.