The government can, via eminent domain. This is how private railroads in the US were financed in the 1800s. The companies paid for land at pre-development price

The government can, via eminent domain. This is how private railroads in the US were financed in the 1800s. The companies paid for land at pre-development prices via eminent domain, then built the railroad, then sold the much-improved land at higher prices. Basically, the land appreciation covered the capital costs, and fares only covered the operating costs. Japan and Hong Kong still use this strategy, and the new private railways in the US are attempting to do it as well. (Virgin Trains and Texas Central)