Roads vs Rails vs Skies
When you go to an airport and pay that $10 to $15 airport fees you directly are paying for the airport. The money the FAA gives to the airport ALSO comes from the money you pay when you fly - avgas taxes, airline taxes, etc - all get rolled back to the airports where the money MUST be spent. It cannot be siphoned off (yet!) to pay for rail.
Roads, originally, were paid for by gasoline taxes - and most still are but usually. The percentage is down now since the Feds / States have shows to take the money AWAY from road maintenance and spend on OTHER stuff over the past 50 years - which is why people don't vote for gas taxes increase since there is NO way to stop them from spending that money on non-road projects once collected. That is why they always write "transportation" increase and not "road" in those gas tax bills - they really want to spend it on bike lanes, light rail, High Speed rail, trams etc - anything but roads!
Also thing about this - how many people on a DAILY basis will want to travel from SFO to LAX? 50,000 a day? 100,000 a day? - oh, maybe 2,000 a day instead of flying down there in 1 ?? hours they can take a train and get there in 4 hours - uh no, most people would STILL fly since that is 2.5 FASTER than the train. The Train will have the SAME security requirements as airports one day so that screening time will always be there (the Homeland Security and Transportation department have talked about that coming over two years ago.) You would need 10,000 people a day in each direction - 20,000 full paying customers - just to pay for the maintenance of the lines / equipment. You would NEVER get back the actual costs.
Roads: $1 million a mile. 40 years LATER (if built right the first time) you have to rebuild (every 5 years paint lines). Rail. every 6 months you BETTER check the WHOLE LINE to ensure nothing has happened to the alignment of the tracks or else it crashes.