US has about the same population density as Switzerland in multiple areas that are at least as large: LA, Bay area and especially Philadelphia-DC-NYC-Boston.
So.. how does size exactly stop the US from having the to-date most efficient mass transport? I'm not talking LA-NYC, noone is gonna do that until someone builds vacuum tubes. First you need good local and regional travel.
Switzerland also has to build tunnels, because of the Alps. I am not an expert on US geography, but there seem to be places with many people and much easier terrain to build rails on.
So.. how does size exactly stop the US from having the to-date most efficient mass transport? I'm not talking LA-NYC, noone is gonna do that until someone builds vacuum tubes. First you need good local and regional travel.