While I would love HSR in the US (and there is definitely a pitch to be made for it in the Eastern US where population density is similar to Western Europe) there are negative externalities incurred with high speed rail as well. Metal-on-metal friction caused by going around bends releases particulates as well, and air currents can be disturbed by trains traveling at speeds in excess of 250km/h.

It is preferable to having to drive in back-to-back traffic though, I agree.