there have been other tests of solar roadways - the costs are abysmal, the durability sucks, the efficiency is abysmal.

https://www.sciencealert.com/the-world-s-first-solar-road-ha...

https://www.sciencealert.com/solar-roads-have-finally-been-t...

https://interestingengineering.com/innovation/solar-roadways...

I think its someone pocketing grant money, or stupid bureaucrats spending tax money/grants for green headlines that has allowed those grifters to continue bullshitting people into building these poor decisions as "tests".