answer:You’re quite right, I think, that high-speed rail is best when combined with short-range transportation options at each station so people can get around entirely without cars. The U.S. has a natural disadvantage of large distances between cities except the NorthEast corridor (Wash D.C. to Boston) and along the California coast. And in general our cities are spead out into suburbs. But the NorthEast corridor seems like the best area for high-speed rail as the cities along that line do have more public transport available than most. (Boston, New York, Baltimore, Philadelphia, Wash D.C. have pretty good public transportation systems) Seems to me that both the Dallas-Houston and the Miami-Orlando-Tampa have that frustrating combination of a lot of traffic between them (good candidates for rail) but little supporting public transport within any of those cities (not so good).