I figured this would have already been talked about here but I did a few searches using "solar road" as keywords and didn't find anything here.
I'm sure most of you are aware that Jinan, China has already installed a 1km, two lane section of solar highway, totalling 5,875 square meters which can generate up to 1 million kWh/year. The cost if the solar highway came out to $458 per square meter. More info
HERE
I saw
THIS video a few years back and thought it was an awesome idea, but sadly they just simply are not cost effective.
HERE is an article that talks about the issues the company has had with the panels.
After discovering that they weren't cost effective, I started to think, maybe it's due to how thick and durable they have to make them in order to stand up to being driven on by cars/trucks every day. So I looked to see if anyone had installed some solar sidewalks or bike paths. Turns out they have... Score 1 for the Netherlands, who built a 230ft solar bicycle path. The solar bicycle path did turned out to be much more cost effective than the solar roads but when compared to ground or roof mounted arrays there's simply no contest. The solar bicycle path ($3.7 million) was only able generate 3,000kWh (which is more than they expected) in it's first 6 months, while the same amount of money could have purchased 520,000 kWh of ground mounted solar. For some reason they have called it a success and have expanded the pathway since it's original construction. A little more info
HERE
As much as I love my solar panels, I think for road use we're probably better off with vertical axis wind turbines, like
THIS. Although those have their own set of problems due to having moving parts.