Airport construction follows a similar system. Most airports in the United States are public-private partnerships. They issue Airport Revenue Bonds, which are similar to municipal bonds from a tax perspective, but they're backed by airport revenues, not municipal tax revenue.[2] The airport authority has to pay back the debt through the fees they collect from operators or concessions. The latter is why everything from bottled water to rental cars is more expensive in an airport. It's not just that they have a captive audience, it's that concession sales actually pay for the operation and expansion of the facility.
In both cases - the FAA and capital expenditures - it's mostly paid for by the users, not the taxpayer.
[1] - https://www.faa.gov/about/office_org/headquarters_offices/ap... [2] - http://www.nap.edu/openbook.php?record_id=14041&page=12
Since the subsidy you link to, varied between 70% and 80%, it could still be the case that the Airport system in California got subsidies within a small multiplicative factor over it's entire lifespan compared to the proposed costs of the high speed rail system.
The objections to high speed rail IMHO, aren't 100% based on economics or funding, because other things have gotten massive subsidies, they're also based on a kind of weird political tribe association people have against trains.
Let me quote George Will as an example: "To progressives, the best thing about railroads is that people riding them are not in automobiles, which are subversive of the deference on which progressivism depends. Automobiles go hither and yon, wherever and whenever the driver desires, without timetables. Automobiles encourage people to think they—unsupervised, untutored, and unscripted—are masters of their fates. The automobile encourages people in delusions of adequacy, which make them resistant to government by experts who know what choices people should make.
Time was, the progressive cry was “Workers of the world unite!” or “Power to the people!” Now it is less resonant: “All aboard!”"
So, to some people, trains are a Euro-socialist kind of thing, anti-freedom.
Traveling from SFO to LAX on high speed rail is far preferable to me than driving for 5 hours or a 5-hour airport experience.
Mythbuster's recently tested this, and the actual difference between driving and flying door-to-door was like 15 minutes.
A 2.5 hr train ride would not only be faster, it would be far more pleasant in terms of getting on/off, and in terms of comfort and space onboard.