Superconducting magnetic levitation is the “next generation of transportation,” says a new rail advocacy group that calls itself The Northeast Maglev (TNEM). The group’s proposed New York‐​Washington maglev line has received attention from the Washington Post and Baltimore Sun. TNEM’s claims might have seemed valid 80 years ago, when maglev trains were first conceived, but today maglev is just one more superexpensive technology that can’t compete with what we already have.

Superconducting maglev train being tested in Japan. Wikimedia commons photo by Yosemite.

Maglev has all the defects of conventional high‐​speed rail with the added bonuses of higher costs and greater energy requirements. Unlike automobiles on roads, rails don’t go where you want to go when you want to go there. Compared with planes, even the fastest trains are slow, and modest improvements in airport security would do far more to speed travelers, at a far lower cost, than building expensive new rail infrastructure.

TNEM’s proposal is to use a new maglev technology called electrodynamic suspension using superconducting magnets. Ignoring the gee‐​whiz terminology, the basic advantage is that it is supposed to be able to go a little faster than previous maglevs, but with the disadvantage that the levitation fails to work at slow speeds so wheels must be added to the carriages.

Japan plans to use this technology to build a line from Tokyo to Osaka that won’t be completed for 14 more years and is estimated to cost $350 million per mile. That compares with Amtrak’s proposal to rebuild the Boston‐​to‐​Washington corridor into a true high‐​speed rail route at a cost of about $250 million per mile. To be fair, Japan’s cost is high partly because they expect to dig tunnels for much of the route. But even TNEM estimates that a Baltimore‐​Washington segment would cost “somewhere north of $10 billion,” or about the same, per mile, as Amtrak’s plan. Such early estimates are always well below final costs.

Maglev’s advantage over conventional high‐​speed rail is supposed to be that levitated vehicles can be frictionlessly propelled at high speeds. But that doesn’t mean they are energy‐​efficient: it takes a lot of energy to levitate a train car full of people. One study by a pro‐​rail group estimated that maglev would require several times more energy per passenger mile as conventional rail technology and have the least effect on reducing greenhouse gas emissions.

Rail advocates point to “successful” high‐​speed rail lines in Europe and Asia. But one point escapes their attention: high‐​speed trains have succeeded in capturing passengers away from low‐​speed trains, but nowhere have they captured significant numbers of passengers from cars or planes.

When Japan opened its first high‐​speed rail line in 1964, rails accounted for 70 percent of the nation’s passenger travel. Today, it has many more high‐​speed lines, but rails account for well under 30 percent of passenger travel. Similarly, in 1980, before any high‐​speed rail had been built in Europe, rails accounted for 8 percent of western European passenger travel. Today, with high‐​speed trains in France, Germany, Italy, Spain, and other countries, rails account for about 6 percent of passenger travel.

The only truly high‐​speed maglev line in operation connects the Shanghai airport to downtown Shanghai, 19 miles away. Though the train has a top speed of 268 mph, it attracts enough passengers to fill only about 20 percent of its seats because, people say, it doesn’t go where they want to go.

Rail advocates argue that, given travel times to and from airports, high‐​speed rail can be competitive with air for downtown‐​to‐​downtown trips. But most people no longer live or work near downtowns. Given multiple airports around Washington, New York, Chicago, Los Angeles, San Francisco, and other cities, most people are still going to find air travel faster, not to mention less expensive (unless taxpayers also subsidize rail operating costs). The main people who work downtown today are bankers, lawyers, government bureaucrats, and lobbyists–not exactly the first people you think of when asked who deserves a transportation subsidy from taxpayers.

So if taxpayers spend $117 billion on Amtrak’s plan for high‐​speed rail between Boston and Washington, or $165 billion on a maglev line over the same route, we can expect that nearly all the passengers on these trains will be people who would have otherwise taken earlier Amtrak trains. To cover operating costs, fares will be so high that only the wealthy will ride the trains: While Megabus charges about $15 to go from New York to Washington, Amtrak currently charges about $150 to ride its Acela over the same route, and that $150 doesn’t pay for the capital or maintenance costs needed to keep the trains running.

Meanwhile, Eric Jaffe at The Atlantic argues that Republicans killed Obama’s high‐​speed rail plan simply in order to discredit the administration. In fact, Obama’s plan would have been a fiscal disaster, ultimately costing taxpayers close to $1 trillion to provide a disconnected transportation system that few would have used. While the Interstate Highway System, which was entirely self‐​funded out of gas taxes and other user fees, connects all major urban areas and carries about 20 percent of all passenger travel and more than 10 percent of all freight in the United States, Obama’s high‐​speed rail system would have been lucky to carry 1 percent of passenger travel.

New transportation technologies are successful when they are faster, more convenient, and less expensive than existing technologies. Maglev and conventional high‐​speed rail are less convenient than driving, slower than flying, and far more expensive than either. Far being an idea whose time has arrived, they are an idea that has already left the station.