Something similar is already the case with other infrastructure in many countries. For example, in my country the company providing my electricity connection i

Something similar is already the case with other infrastructure in many countries. For example, in my country the company providing my electricity connection is (by law) separated from the one which sells me the actual electricity. This means I can choose one of a dozen or so companies who do the whole electricity market thing to sell me power at the best price possible, and being charged a fixed fee for the hookup regardless of which company is selling the power to me. The same thing applies to gas and (to a very limited extent) telephone/internet. The companies owning the infrastructure are usually owned by the local governments, so they do not really have an incentive to generate a profit. The same applies to railways. One state-owned company manages the rails itself, and everyone who wants to run trains on it pays them a usage fee. It's the only solution to deal with natural monopolies like this, really.