[coredog64]

Which parts are they going to hit 200mph on? I have driven extensively on 8, 10, and 40 into and out of California, and I can't recall a path that doesn't transit the North American Cordillera: https://en.wikipedia.org/wiki/North_American_Cordillera

On 8 heading out of San Diego, you go from sea level to 4000 feet, down to (IIRC) 3000, and then back up to 4000 before going back down to sea level. Once over the Arizona border, you pretty quickly go from sea level up to about 2000 feet.

40 goes through Flagstaff, the elevation of which is almost 7000 feet. Albuquerque is at 5000 feet.

So, where in the world do you find HSR that transits not one, but three or four 4000 foot passes?

[jhgb]

Gotthard Base Tunnel is rated for 140 mph, not quite 200 mph but close. It has a maximum depth of 8000 feet. Would something like this qualify for the route across the mountains? Optimal train path would probably be somewhat different from the current road network anyway, so road examples provide only approximate information about railway network construction difficulty.