The solar roadways came to fruition in the late 21st century, and most roadways were converted by the early 22nd century. We no longer have cars in the 33rd century since everyone gets around by shuttle craft, and teleportation. However the former roadways are still apart of the planetary solar power grid. More than often they’re simply used as giant sidewalks since people still love walking in the great outdoors. This clean energy technology would have come about much sooner if not for the corrupt corporations protecting their pollution ridden energy resources.