The next generation of passenger trains will literally fly. On test tracks in West Germany and Japan, passenger trains swoosh along at more than 250 miles an hour, but metal never touches rail. These trains hover over their guideways by a force known as magnetic levitation, which gives them their name, mag-lev.
Now foreign manufacturers are beginning to peddle mag-levs in the United States, where some transportation officials see them as an alternative to expensive highway construction and overcrowded airports.
John Parke Wright IV, chairman of the Florida High Speed Rail Committee, envisions a mag-lev demonstration model that would whisk tourists and sightseers from Walt Disney World to Cape Kennedy, a distance of 50 miles, in seven minutes.
Las Vegas city leaders are talking about connecting their city and Los Angeles with a system that could make the 275-mile trip across the desert in an hour.
Wisconsin officials completed a $40,000 study in December that said a $1.2 billion mag-lev train could be built between Milwaukee and Chicago in time for the 1992 World's Fair.
''Mag-lev travel is like flying at ground level,'' says a spokesman for the Budd Company, an American railroad car manufacturer which is working with the West German Thyssen Henschel Company to sell mag-lev technology in the US.
''The propulsion system has no moving parts to cause vibration; it converts energy directly into motion,'' he says. ''It is environmentally clean because it uses centrally generated power.'' He also pointed out that the system does not depend directly on petroleum-based fuels, as do other systems.
A mag-lev train now being tested in Japan looks a lot like a giant capsule with windows. The Japanese and West Germans have different variations of the train, but both run on the concept that magnets of similar polarity repel each other.
The train is equipped with electromagnetic side packs which guide it along a magnetic track, Budd Company officials explain. At the same time, levitation magnets push the vehicle up, allowing it to hover above the track. It is propelled down the track by the interaction of forces between the magnets aboard the train and magnetic coils on the sides of the guideway.
So far the systems have only been tested, and most transportation planners consider the technology still too experimental to draw the financial backing needed from banks.
But Mr. Wright is convinced that a demonstration mag-lev system running from Disney World to Cape Kennedy could be the first moneymaking use of the technology in the US. He says he is planning a meeting between Japanese mag-lev engineers and National Aeronautics and Space Administration officials to talk about the idea.
''It could be an extension of Disney World,'' he says. ''People could get on the train at Disney, shoot over to Cape Kennedy Space Center in seven minutes, take a slow ride through the space complex, and then shoot back to Disney.''
Glenn Burdick, dean of the University of South Florida's college of engineering, agrees that a Disney to Cape Kennedy mag-lev would be a ''natural.''
''That's one of my pet projects,'' says Dr. Burdick, who wants to make the university a center for transportation study. ''The ridership suggests itself. It's a short run, and there are a lot of people who would want to take it. The Japanese could not find a more natural place to test the mag-lev technology in the United States.''
If mag-lev technology works there, Wright says, it could revolutionize transportation in the US.
''Mag-lev is the most fabulous ground transportation system produced by man, '' says Wright, who saw a demonstration of it in Japan. ''It's staggering.''
Some transportation planners question whether the extra speed the mag-lev can produce over conventional high-speed-rail trains would make a significant difference in the comparatively short runs the trains would make. They also ask whether the mag-lev would require substantially more energy.
In its study for Wisconsin, the Budd Company said building a mag-lev system would cost less than a conventional rail system. Other rapid-transit systems would cost between $16 million and $24 million a mile to build, it said, while mag-lev's projected costs are between $12 million and $15 million.
A Japanese high-speed railroad engineer said that mag-lev uses only a little more energy than a standard high-speed-rail system. ''Mag-lev is specialized for long-distance, nonstop travel,'' he said.
Wright said mag-lev systems could eventually connect all the major cities in the Southeast, and the technology would allow towns as far as 300 miles from urban centers to become suburbs.
''But we're being cautious about mag-lev,'' he said. ''We're not dealing in pipedreams, but in realities. But if mag-lev is feasible, we want the most innovative system we can get.''