France to pave 1,000km of road with solar panels 10 years ago
Thank you, that was my point as soon as I heard about "our" roads being made into non efficient solar panels.
However, given the few experiments conducted so far, it seems that it wouldn't be any more efficient than solar panels, moreover, the technology to cover roads with piezoelectric sections hasn't been tested out of research, AFAIK.
Here is a short "descriptive" made about 2 years ago : http://large.stanford.edu/courses/2012/ph240/garland1/