No prior experience in building and operating high speed rail.

Track standards must be much higher.

Track must be completely secure from people and animals, and geology. This means high fences and shallow cuttings set far back from the running lines.

The line can only be crossed by bridges or tunnels. No level crossings.

Long distances pose issues in crew turnaround.

Track must be as straight and flat as possible. North America has space, but also has geography.

Reliable catenary power supply.