This is how train networks the world over were built, with train companies buying up land and then developing or leasing it out after their railways made it valuable. It's how successful transit companies operate in Asia and remain profitable, building shopping malls and hotels on and around their stations.

It doesn't require population density (that comes after the development), it doesn't require government support (although it helps, especially if the government is subsidizing roads), but it does require investment and long-term planning.