Wasn't there a stipulation in the original Amtrak
contracts that stated they are the sole passenger train
provider on the routes they serve.

Thus, the railroads were free to run what they want
on their own routes not served by Amtrak?

If that's still true then it's going to
be tough to fine routes, but if you look at a map
not impossible, just not always practical.

And the other nagging issue with insurance is
the railroads are usually self insured. so if you
have another agency providing coverage won't they default
to the deeper pockets of the railroad first,
before paying out a claim?

Sorry, more questions than confirmed facts.

-k-