A grand plan to double track length to 120,000 kilometres between 2010 and 2015 is likely to cost over $100 billion a year. It’s worth it. As well as comfort, prestige and low emissions, rail is the ticket to better urbanization. A recent World Bank report calculated that the benefits to a city of better connectivity from high-speed rail could be almost as large as those from saving passengers time and operating costs.

The funding, though, has been pure folly. Projects depend on borrowing from Chinese state banks and issuing bonds — which in turn are mostly bought by the banks. The resulting debt, on a notional 6% interest rate, would require $25 billion a year of interest payments. Passengers aren’t rich enough to cover that cost.

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It’s not too late to turn things around. The first step is to admit that the government must pay a share. Even successful rail networks like Sweden’s and Japan’s have depended on subsidies and bailouts. It would make sense to turn a chunk of rail-related borrowing into straight sovereign debt, and relieve the newly created China Rail Corp of having to repay it.

Then there’s future investment. Here, it makes sense to link costs to benefits. China could learn from Hong Kong’s mass transit system, which is funded partly through government grants of land. New lines boost land prices, which the operator can either develop and sell, or use as collateral for loans. When Hong Kong’s MTR listed in 2000, property made up 15% of its total assets — by June 2012, it was 32%.

Finally, funding could come from those who benefit most: heavy industrial companies. Shifting passengers off low-speed lines will relieve chronic overloading. Freight traffic has tripled since 1990, and as much as 40% of what rides on the rails is coal. Charge users — notably state-owned enterprises — their fair share, and China’s railways don’t have to end in financial wreckage.

Read more at Reuters Breakingviews.