Check out Stephen Smith’s fascinating look at the survival of for-profit rail systems in Japan:

Beyond the astonishing size and quality of the networks, Japan’s three major metropolitan areas, sometimes called the Tokaido megalopolis after its Edo-era road, are also home to a vibrant free market in transportation. Singapore and Hong Kong also have private companies, but competition is weak compared to Japan’s dizzying array of independent firms. Japan has by no means a completely free transportation market – even the private companies receive low-interest construction loans and are subject to price controls and rolling stock protectionism – but at the moment, it’s the closest thing this planet has.
Japan followed a similar path as the West before World War II, but afterwards diverged. As in the West, railroading started out very laissez-faire in the 19th century, but came under state control in the beginning of the 20th. But after World War II, while nearly all railways and intracity buses in Europe and North America were nationalized, Japan stayed its pre-war course, with the railway industry retaining its sizable minority of private firms.

And while mass transit in North America has languished, Japanese mass transit has proven astonishingly successful.