All this talk of rail transit is great, but so little of America is an urban center like Europe. In our spralling cities, even if mass transit was available from the burbs (system #1) you still have the problem of serving all the corporate parks (#2) which aren't even walkable themselves (#3)! So at minimum a three tier system which only serves the main industrial/commercial centers and would make for an insane commute! Geographically speaking, most of America isn't ready for this. If we're just solving a fuel issue, there are better solutions.
