That's very cool. Here in Oz our roads are all asfalt, while in the US they're either asfalt or concrete. Concrete is meant to last a lot longer and require much less maintenance, but costs a lot more. If the guy in the video is right (and probably is), the cost of asfalt will go up making it more attactive to build concrete (in the US atleast) - unless they start using bio-fuels, etc. Although, the flying car might make this redundant.
I love the multi-function of the road: not just a solar collector, but pressure-sensitive, signage and data transmission too. You can imagine the lines on the roads themselves will one day be lit and not painted, dynamically changing to suit the conditions of the minute. How about the automatic "display" of a motorcycle lane in between cars when a bike is detected!... Yeah!
I guess the solar road is several times (if not 100s or 1000s) more costly. However, manufacturing costs will come down eventually. We also have to consider the environmental cost of manfuctuing. I understand concrete is nasty and produces lots of pollutants in the process, and production of electronics has a similar nasty by-product.
Regardless, it's amazing what these Sheldon Coopers keep coming up with. Thanks for the post Dave.