Great ideas, but you're talking about a system, not just a line. And going to that many places, it would look sort of like BART ... light rail on steroids, with fewer stops so speeds could be reasonable. But you have to start somewhere, and connecting two of the biggest cities in the state, that aren't that far apart, is a good place to start.

Bob's correct, though, regarding UP. They would definitely want the passengers to be on separate track. So Phoenix-Tuscon (perhaps via Tempe?) would need to be a complete new railroad, certainly with passing sidings and possibly with extensive double track depending on the level of service.

This wouldn't by any chance have some connection to the PHX airport trenching project that was discussed the other day, would it? Make it wide enough for 3-4 tracks?