Aug. 1 (Bloomberg) -- Shanghai spent $1.25 billion building the world's fastest train to the city's Pudong International Airport. Cindy Huang would rather catch a bus.

The 50 yuan ($6.60) train fare is too costly for most Shanghainese, says Huang, a human resources officer. The magnetic-levitation, or maglev, line also terminates in Pudong's suburbs, 12 kilometers from downtown, meaning most travelers must get other transportation to reach their final destinations.

``It's much more expensive and time consuming to take it,'' says Huang, who has made 11 trips on the 431 kilometer-per-hour train, mostly escorting visitors to the city, China's financial hub. ``It's not my choice if I travel on my own.''

Shanghai authorities have put on hold plans to spend $5.3 billion extending the 30-kilometer (19-mile) line -- the world's only commercial maglev train. The project has been plagued by ridership that is less than a quarter of what was expected, protests by residents concerned about radiation and construction costs twice those of other high-speed trains.

Cancellation may force Siemens AG and ThyssenKrupp AG, the maglev's developers, to scrap the 73-year-old technology and write off at least $2 billion in costs, says Gerd Aberle, a professor of transport economics at Giessen University in Germany.

``It's the last chance to convince the rest of the world that the maglev is an interesting system,'' he says. ``If it's not realized in China, that may be the end.''

Aberle headed an advisory committee that rejected plans for Germany's first maglev line, from Berlin to Hamburg, in 2000.

``The economic basis is very, very weak'' because Germany already has a high-speed rail network, Aberle says.

Electromagnetic Forces

Unlike traditional trains, maglev models lack wheels and rails. They hover about a centimeter above their tracks, held and propelled by electromagnetic forces.

The first commercial maglev line opened in 1984 and covered 600 meters from the U.K.'s Birmingham International Airport to a railway station. It closed in 1995 after becoming unreliable. Canada, Germany and the U.S. have all built test lines, using various technologies. Japan, which developed a hybrid system, opened a 9-kilometer urban track in 2005.

China isn't the last chance for maglev trains, says Peter Wiegelmann, a spokesman for Berlin-based Transrapid International, a Siemens-ThyssenKrupp joint venture. Potential markets include the U.S., Germany and Middle East, he says.

Nine maglev lines are under consideration in the U.S., including projects in California, Florida, Maryland and Pennsylvania.

``We are optimistic,'' Wiegelmann says. ``The Transrapid fits especially well in countries that don't have strong rail infrastructure.''

Future of Travel

The U.S. should get on board, says Peter Miller, 54, a Tennessee-born freight salesman who lives in Shanghai. Fast trains may help wean the country off polluting autos, he says.

Maglev is the future of train travel, says Sun Zhang, a professor of engineering at Shanghai's Tongji University and a member of the maglev planning committee.

The Shanghai government plans to extend its line 200 kilometers through the city center to Hangzhou, including a 35- kilometer detour to the domestic airport.

Authorities now are assessing environmental and health impacts, says Jiao Yang, a Shanghai government spokeswoman. The extension, approved by the central government last year, hasn't been shelved, she says.

Building costs of $26.4 million a kilometer, twice as much as high-speed railroads, will fall as more lines are built, Sun says. Chinese are learning the system by working with Munich- based Siemens and Dusseldorf-based ThyssenKrupp.

`White Mice'

China ``isn't doing this for profit, but for prospective research and grasping the key technology,'' he says.

Some Shanghai residents are concerned the maglev may emit radiation. More than 5,000 petitioners complained to the district government in a single day in March, the Xinhua news service reported May 27.

``We don't want to be white mice to test the influence of magnets,'' says a man who gave only his family name, Gu, adding that he feared reprisals for speaking out.

In Wanbang City Garden, where Gu lives, the government has postponed plans to relocate some residents.

``No one knows what's happening,'' says Lu Xingqin, head of Wanbang's community office.

A 2005 study of maglev lines by the Pennsylvania Transportation Department and the Port Authority of Allegheny County found ``no impact'' from radiation.

`Vanity Project'

Samuel Gong is more concerned about convenient connections. Routing the maglev line through the city's main railway station will help, says the Shanghai-based marketing manager.

The train's speed symbolizes Shanghai's economic growth and impresses visitors, says Gong, 28. Tourists on board take photographs when speedometers flash 431 kmh.

Still, the cost of the line makes Gong flinch.

``It's a vanity project,'' he says. ``When I see the farmland outside the window where the maglev train runs, I feel bitterness for the wide wealth gap in the city.''

The train carried 11 million passengers from December 2002 to the end of May this year, according to Sun. Transrapid predicted at least 10 million a year.

``It's a fascinating technology,'' says Dominik Samuelis, a teacher from Aachen, Germany, preparing to board in Shanghai. ``I would like to see the same thing in my country.''

To contact the reporters on this story: Irene Shen in Shanghai at ishen4@bloomberg.net; Lee Spears in Beijing at lspears2@bloomberg.net.

Last Updated: July 31, 2007 21:57 EDT