My take is, if you really think about whats involved in doing something like this it just seems completely unviable.
The cost of designing, manufacturing, installing, trouble shooting, maintaining, and further developing a programmable infrastructure would be enormous. You're paying skilled technicians to build a road by the quite labor intensive square inch at a time, instead of just resurfacing asphalt in large runs at a time. Keep in mind you certainly still need a solid surface to put these on, I doubt you just plop them in the dirt.
How many iPads would it take to cover every square inch of just the I-15 corridor? (the main difference being iPads are cheaper to make)
Rooftop solar, being highly optimized, is only barely lucrative in certain situations. These things being mounted at the lowest point puts them in shadows very early and being mounted upward facing (not solar facing) gives non-incident angles which further decrease efficiency. The non optically clear lens over them would absorb most of the solar energy, (even optical quality glass lenses can absorb a substantial percentage). Road grime would play a large part in keeping the panels dirty, leaving you with an expensive plastic road until they're cleaned and can produce electricity again. Keeping snow/ice melted in the infinite heatsink that is the outdoors in the winter would take a huge amount of energy, more than the things would produce in quite some time. Most electronics have a hard time not failing on a desk where thy're not being run over by the stresses of millions of pounds a day.
The most expensive, tricked out, completely unnecessary parking lot on earth? yeah... you might be able to sell that in the mac store.
Make a solar roof shingle instead, at least it goes unmolested for years at a time and can possible give you a decent roi.