Transport for London is a pretty tightly run ship. Only capital city in the world that doesn't receive operating subsidy for its public transport. Not that that is a good thing necessarily as the tube is expensive to use relative to Paris or Berlin but a pretty impressive achievement considering the ancient complexity of the whole thing.

Scotrail is run by the Scottish government and has been steadily electrifying the Scottish rail network and because of the slow and steady nature of the work, between them, Network rail and the OHLE contractors they have got the cost for this down to 5 times less per km than typical UK costs previously e.g. the great western main line.

The moral of the story is get good people, give them stability and a clear goal and they will do great work. It doesn't really matter if they are working for the government or the private sector.