content: I was thinking about all of these myself. I chuckled at the thought of them trying to use these most places. Even in large, relatively flat cities where you have a "grid" there are still changes in grade. The roads aren't perfectly straight, the intersections aren't perfectly square. There are under and over passes. That's in the ideal scenario. Less ideal would be some place like San Francisco where you'd just about need to anchor these panels to the ground so that they don't slide down the hills. Repairs will be "fast" but how fast will they really be if you have to replace rewire and replumb everything that was previously running through that section? Where will the cars that need to use that road go if you're closing the whole width of it down? Most repairs are scheduled and organized so that traffic can flow even while work is being done. If a single section of road spans the entire width and you have a hole where the road used to be, that won't really work. The entire idea seems like a poorly conceived college project.