system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why doesn't the United States have bullet trains?
gpt
The main reason is that aside from the northeast corridor from Washington DC to Boston, the national passenger train company (Amtrak) doesn't own any rail.

It leases time on tracks from freight operators. And since it operates on the same lines as freight trains, all of its engines and passenger cars have to be rated to be passenger survivable in a collision at maximum speed with a freight train. This imposes heavy weight requirements on them.

Way out in the west even a regular Amtrak passenger train will do 80mph.