The US nationalize Amtrak because the railroads were going to stop doing passenger service all together. But 100 years ago rail in the US and Britain were busted out. The British nationalized their rail. The US turned rail into a semi-regulated monopoly. Notable in the US due to geography the economy depends on freight rail to move bulk goods at least part of the way.

Writings I've seen basically say transportation systems fail under the free market eventually.