I would argue the opposite. We don't *need* 79 mph rail. Outside of the gravitational fields of very large cities 79 mph trains will never amount to more than a marginal share of intercity traffic. It's nice to have, it's more comfortable than the bus, and it might in best cases be time-competitive with the car, sure, but it's not terribly attractive to many people, and if the 79 mph intercity network we have went away hardly anyone would notice. In a country the size of the US, if rail is to ever be a 'need,' something to replace as many car and air trips as is reasonable, than it needs to be fast, frequent, and reliable in a way that the legacy system has been unable to deliver since the age of the streamliner.
B. Dawe's map of routes and urban populations https://brendandawe.carto.com/viz/80b9d ... /embed_map" onclick="window.open(this.href);return false; NOW updated with 2016 Canadian Populations