President Obama’s high-speed-rail proposal will, over the course of six years, pour $53 billion of taxpayer money into a megaproject that produces little value for the vast majority of Americans. It uses the classic pork-barrel strategy of starting a program small and then expanding it after Congress, prodded by special-interest groups, is fully committed.

Secretary of Transportation Ray LaHood admits Obama’s 25-year plan to extend high-speed train service to 80 percent of Americans will cost $500 billion, which means after six years, spending will have to increase to $24 billion a year. While this will please construction and engineering firms, the rest of us will get little other than the satisfaction of knowing our trains go as fast as those in France and China (though less than half as fast as planes).

The real value of any new transportation technology comes from the new mobility it creates. For example, the average American travels 4,000 miles and ships 2,000 ton-miles of goods per year on interstate freeways, virtually none of which took place before the interstates were built. That new mobility helped people reach jobs and other opportunities and ship products that might never have existed without the interstates.

In contrast, high-speed trains will produce almost no new mobility — in fact, they could suppress freight mobility, which is why the freight railroads are resisting government plans to use their tracks for high-speed passenger trains in North Carolina, Virginia, and Washington. The Florida Department of Transportation predicts 96 percent of the people riding its proposed Tampa-to-Orlando high-speed train would otherwise drive; only 4 percent will be new travelers. With 50 million people visiting Central Florida each year, high-speed rail will increase business by less than .25 percent.

Similarly, the California High-Speed Rail Authority predicts 98 percent of the riders on its proposed San Francisco–to–Los Angeles high-speed trains would otherwise drive or fly. With only 2 percent new travel, the trains will create almost no new economic opportunities.

Far from serving 80 percent of Americans, Obama’s trains will serve only about 8 percent. High-speed rail’s main market is downtown-to-downtown travel. But little more than 7 percent of Americans work in big-city downtowns, and fewer than 1 percent live there. Few aside from this fairly wealthy elite will regularly ride high-speed trains.

For the few who use it, high-speed rail will substitute an expensive form of travel for much more affordable forms. Fares on Amtrak’s Acela average nearly 75 cents a passenger mile, compared with average airfares of 13 cents per passenger mile and bus fares that are even lower. New York–to–Washington tickets on the Acela start at $139; JetBlue starts at $39; and Megabus averages less than $15.

Americans spend an average of 35 cents a vehicle mile on driving, and cars in intercity travel carry on average more than two people, so the cost per passenger mile is around 15 cents. Subsidies to airports and highways add only about a penny per passenger mile to these costs. The Acela’s high fares explain why it carries only 2 percent of passenger travel in the Boston-to-Washington corridor.

Unlike the interstates, which were paid for exclusively out of gasoline taxes and other highway user fees, all of the capital costs and much of the operating costs of high-speed trains will be subsidized by taxpayers who will rarely ride the trains. This is the way it works in France and Japan, where — despite having population distributions much more conducive to rail travel — residents ride high-speed trains an average of less than 500 miles a year.

Nor will high-speed rail offer any environmental benefits. The average intercity auto trip today uses less energy per passenger mile than the average Amtrak train. While it takes a lot of energy to move trains 150 miles per hour or more, autos are getting cleaner and more energy-efficient every year, so by 2025 the average car will be greener than the most efficient train.

High-speed rail will do little more than drain our economy. It is foolish to ask taxpayers to spend hundreds of billions on trains that few can afford to use.