You know what the procedure is to fix a diesel oil spill? They dump fine grade sand on the spill then scoop up the sand with the fuel. Now, think for a second. Cars, running over a fine grade sand with a binder on your fancy glass panels. These things will need to be swapped out every time there is a fuel spill.
That is even before we get to the nonsense of putting a solar panel on a surface that is going to have objects blocking the sun most of the day. Then the cracks in the panel will allow water into the roadbed (this is bad).