What suggests that it's many years in the future? I've always thought of it as being set after an apocalyptic event in current times, (21st century), and we were all the survivors? Rusty cars, traffic cones, wooden pallets, and 'Do Not Enter' signs would all fit in perfectly with this. I know there was some talk of futuristic "caretaker" robots, but I thought this was all just exploratory concept art. Everything currently in-game suggests a current day post-apocalyptic scenario.
I think roads are planned, or at least being talked about. I have heard talk of procedural roads, (which Rad Towns can presumably spawn along), and also talk of naturally occurring roads based on foot-traffic, so that the paths that users take most frequently naturally evolve into roads. I very much like this idea...
Yep. Notice I never said there IS a tone problem, but there COULD be. If you check the concept art section of trello you'll see lots of stuff that would look very out of place in the 21st century theme. Personally tho, I like the 21st century look better than the future look.