" Once the glass breaks, it's stays broken"
Modular construction. Been around for ages for PV.
"Debris will scratch the glass making it more translucent rather than transparent reducing its effectiveness"
A simple lesson from Moh's Hardness scale might change your mind on that, assuming you even know what that is. We've got transparent glass harder than anything used in nearby construction or even car construction.
"Roadways don't track the sun making solar cells much less efficient"
We've got optics that can focus from any angle, no need to track the sun.
" LEDs aren't visible in direct sunlight especially at shallow angles"
Absolutely wrong. We've got LED-lit crosswalks here in Riverside that flash very brightly, covering roughly half a sphere of incidence, and can be seen several blocks away in broad daylight. Bear in mind this is practically the southern side of the MOJAVE, not many more places get as much sun as we do.
" The glare from any reflected light will blind drivers."
As if that doesn't already happen with heat-mirrors made on the road surfaces.
" As he rightly points out, putting the solar cells NEXT TO the road works much better. There's simply no reason to put them IN THE road even if it did work. "
He's very obviously not an engineer.
"And the idea of putting it in parking lots is even dumber. Yeah, parking lots where cars are parked on it during the day"
And now you're taking his same and stupid assumption that cars would be there all the time.
Protip: Most parking lots usually run about 1/2 capacity, excepting holidays. Oh, and you forgot incidental reflection of sunlight from car bodies. There's still a MINIMUM umol of 400 even under the shadow of a vehicle in a parking lot (I've measured this with a quantum meter at high noon) which is still plenty of harvestable energy.
Quit listening to someone that doesn't even have the proper equipment to test out his nonsense, and obviously hasn't even been out in the actual field to conduct real on-site research.