Why do you sometimes see things that look like long black bungee cords stretched across the road? The only possible use for them that I can come up with is that maybe they’re somehow part of something that counts how many cars pass over them.
For bonus points, why (at least in New York) do I see signs on highways that say “Road Service By Permit Only”? Somehow I don’t think there’s a huge problem with unauthorized road construction. (“Hey, Joe, you wanna go over to the Bronx River Parkway and try out my new steamroller?”)