Subway systems in NYC, DC, etc get heavy use.

America is slowly adding private lines in the absolutely most cost effective locations with low cost of construction + high potential ridership. That’s a sign we’re underinvesting vs other countries who already have service along such routes and are more debating heavily government subsidized expansion for existing networks.

I suspect the vast majority of passenger miles on rail in the USA are local transit and light and heavy intercity short-commute rail.

Not the long-distance Amtraks across the country.

I guess I should have used a different word but I meant huge to imply a large population as well as area. The US is the 3rd most populous country in the world after all.