I actually love seeing the "pavement lights" in NYC when I walk past them, or recognize that I'm walking under them. At this point, I know they're purely decorative, but it was a nice touch and something idealistic that left behind something cool. As far as what I was thinking on sidewalks, the other response got it right; I was thinking of putting archways and solar roofing over sidewalks. It doesn't need to be high-yield, but the benefits really sound like they outweigh the risks (as a pedestrian) - keeps the sidewalk in shade, keeps the rain and snow off, and generally would make walking a nicer experience. I've been on covered sidewalks before (including the ubiquitous scaffolds in Manhattan, Hoboken, and Jersey City - I used to aim to walk by the buildings I knew had scaffolds up when the weather was bad out), and it's a better experience than just being outside. Plus, if it's covered well, I think it'd reduce the opportunity for pedestrian vehicle accidents; just from having less possibility of people and cars interacting.
EDIT: Also, thank you for answering about the road idea, it was a thought. Too bad it doesn't work. :-P
EDIT: Also, thank you for answering about the road idea, it was a thought. Too bad it doesn't work. :-P