Damn, this technology has more Pitfalls than the Atari 2600 game. It's basically laying down thousands of low-tech iPads (they want to include piezoelectronics as well) under a piece of thick glass and putting as many technology in as possible.
It doesn't take long to come up with serious challenges: from environmental (adapting to temperature and moisture, using tons of electronics and not screw up the earth: replacement rate?) to the materials (making it easy to replace but keeping its strength, where will they storage the energy, how do you provide enough in the morning rush hour) and safety (how it will reflect sunlight, who will be responsible when (not if) there are erros in the road signs, what about lateral grip in corners, how slippery will it be, especially when icy) come to mind.
I mean, ffs, last month they tried to paint (note: just paint) a road here in the Netherlands with glow-in-the-dark paint to eventually replace lights and it failed miserably because it couldn't withstand the moisture and its reflectiveness didn't last. And this was initiated by Heijmans, a large road construction firm who most definitely has $1mil and a large team of engineers.
This project aims far, far higher and while I applaud people who dream big, this is just so close to impossible I felt the need to say something. Especially because it claims to solve so many problems.