Okay, got it, glass is more resistant to scratching than steel. Now grind sand and rock against either for days, let alone months or years. It's going to lose i

Okay, got it, glass is more resistant to scratching than steel. Now grind sand and rock against either for days, let alone months or years. It's going to lose its optical qualities. Bad optics, no sunlight, no energy or LED light. I _love_ the idea of a smart roadway that helps pay for its self. But I don't think this design hits the mark yet.