I have read elsewhere that there are ways for rail development to capture some of the increase in land value, in order to offset the cost of the development. I do not have any pointers though.
A common example is railroads in Japan, which own the land around the station and either run or profitably lease buildings and services on them, with stations in densely populated areas doubling as shopping centers, hotels etc
In the US, railroads were granted sections of land (1 square mile) alongside tracks.
I believe this was every other section, for each mile of track laid. One site I'm finding says that this extended 20 miles to either side of the track:
Approximately 16 percent of Nebraska’s total land mass was given to various railroad companies, either by the federal government or by the state. Along the lines of the state’s two major railroads, the Union Pacific and the Burlington, every other square mile of land (called a "section") went to the railroads. This checkerboard of land extended back twenty miles on both sides of the track. So, the railroads owned a total of twenty sections of land for each mile of road constructed.
There are some holdings that are still retained (or were until relatively recently). The UCSF extension along the San Francisco bayfront is on land that had belonged to the Santa Fe Railroad, for example.
How US High Speed Rail projects are utilising this approach I don't know. Much of the valuable land is, of course, presently owned.
I believe this was initially specified under the 1862 Pacific Railroad Act, and may have been later amended:
Section 3 [of the Act] granted an additional 10 square miles (26 km²) of public land for every mile of grade except where railroads ran through cities or crossed rivers. The method of apportioning these additional land grants was specified in the Act as being in the form of "five alternate sections per mile on each side of said railroad, on the line thereof, and within the limits of ten miles on each side" which thus provided the companies with a total of 6,400 acres (2,600 ha) for each mile of their railroad.
The standard land grant pattern for railroads was a checkerboard pattern, which makes it hard to depict accurately on a map. The source I have doesn't give an exact number of Nebraska that was actually granted in land grant to railroads, but 16% is right in the ballpark of what I'd estimate from interpolation from other states.
However, it's also worth noting that land grants were only doled out in US history in an extremely limited time period--from the 1850s to the 1870s. The majority of railroads were not in fact built with land grants.
I was aware of the "checkerboard" land-grant allocation, but not how deep (perpendicular distance from RoW) it went.
I also wasn't aware of how brief the land-grant subsidy era was. Though it would be interesting to see a track-mileage development timeline or animation showing how trackage developed over time.
My general understanding is that track mileage exploded quite quickly, often with competing railroads establishing duplicate connections especially on highly-attractive routes, with the winner then absorbing (or simply competing to death) the loser(s). There is also a distinction between major (national or regional) Class I railroads, and short-line (usually Class III) railroads, where a short-line often served only a single line or small set of lines within a small region.
Overall, US railroad trackage shrank for much of the 20th century as early, redundant, competitive trackage was abandoned. I'm not sure what recent trends have been.
