> In the UK's example, nationalization fostered trade (the roads were all toll roads previously). In the case of the US railroads, nationalization can arguably be seen as a disaster so there are mixed results of this.

It's a mixed bag all around, this one. The railroads in the US were killed, for the most part, by the Interstate Highway system, an equally nationalized endeavor. But really, they were doomed by geographic reality. Population density in the US is such that in most parts of the country a car is an absolute requirement for every working adult. And gas is cheap enough (relative to the rest of the world) that it's cost effective to rely on trucks and airplanes to move merchandise.

If you privatized Amtrak tomorrow, you'd still see full rail service up and down the Boston-NYC-DC corridor. But running a train through "flyover" country is a waste of money from the get-go.