Solar roads and sidewalks are a PR stunt. Abrasion is no joke, nothing optically transparent survives on the ground. You can see this easily in the cellar "pavement lights" common in NYC and other old cities. Light still passes through after a century, but maybe 20% and very diffuse. Bad for solar panels.

Roads don't absorb enough energy to generate power, they're not flexible enough. They're designed to not absorb energy since it hastens breakdown. Potholes are a good example of a road surface energy absorber :) .

Solar roofs are a far better bet. Elon is onto something there, but time will tell if costs can be brought down enough. Besides the good PR, solar roofs substantially reduce heat absorbtion, important in the sunny climates solar works well in. And we have a ton of wasted roof space. Many companies would willingly allow roof panels to be put up for free if the economics for power generation were good enough.