Railroad vs. airport vs. highway funding - a point to ponder

Amtrak President and CEO Joseph Boardman as cited by PolitiFact:

In the forty years of Amtrak’s existence, the Federal government has invested a total of $36 billion in the Amtrak system – a figure that represents both operating and capital funding. Between 1971 and 2008, by contrast, the Federal government has invested more than $421 billion in aviation and over a trillion dollars in the nation’s highways.

By comparison a high-speed rail network for California, connecting San Francisco to Los Angeles and Anaheim has been estimated as costing about $69 billion. Of course there's definitely a lot more people using both the airports and the highway system, but with large-scale investment in high-speed rail that figure might shift somewhat.

I found a 1997 study that considers high-speed rail the most expensive option but (a) it doesn't seem to include any real analysis of fuel cost and (b) it's time-cost analysis seems off (i.e. it seems to account only for travel time and not the time to drive too/from the airport and cost of security/boarding delays) both of which seem likely to increase the appeal of rail over flying.