Is that dedicated lane cheaper? In many cities that are facing a traffic crunch, they've already made all of the "easy" road improvements -- for example, 101 in

Is that dedicated lane cheaper? In many cities that are facing a traffic crunch, they've already made all of the "easy" road improvements -- for example, 101 in the SF Bay Area is pretty much all built in to the center median, so adding new lanes means adding outside lanes (which requires rebuilding every bridge and intersection). It'd be cheaper, of course, to take an existing lane and convert it to a bus-only lane, but that's politically infeasible.