A year ago, Volkswagen in China launched a marketing campaign called The People's Car Project (PCP), which invited Chinese customers to submit ideas for cars of the future. Participants were able to tinker with designs on a Web site that Volkswagen set up for that purpose, or they could upload their own designs. Wang Jia, a student and resident of Chengdu in the country's Sichuan province, chose the latter, envisioning a two-person environmentally-friendly hover car.

Jia sent sketches of a levitating car that could be maneuvered easily in a downtown setting, says Simon Loasby, head of design at Volkswagen Group China. The VW team rounded out the design. "We put a concept together, including a video depicting how it would function," he adds. "It was the ultimate in dreaming because a full-scale version of the car doesn't exist."

The imaginary car stays aloft with the aid of magnetic levitation, much the way some maglev trains travel along special rails using electromagnetic suspension. (Other maglev trains use electromagnetic forces for propulsion without actually lifting the train off the ground.) The Shanghai Maglev Train has been ferrying passengers since 2004 on a 30-kilometer line between Pudong International Airport and the city's outskirts at speeds of up to 430 kilometers per hour. Magnets on board and in the track lift the train between eight and 12 millimeters, depending on how much electrical current is used.

What keeps maglev vehicles from gaining widespread use is the need to set up an infrastructure of electromagnetic rails and roads. In their video, Volkswagen designers envision a scenario where magnetic iron rock or ore beneath Chengdu help create the car's levitation; alternatively, the minerals could be mined and mixed in with the tarmac. "We built a one-quarter scale model of the car and used a bit of creative filmmaking to show how it would work," Loasby says. As portrayed in the video (see below), the vehicle would be about two meters in diameter and about 1.5 meters wide.

In the video, Jia's parents take the wheel-shaped hover car out for a spin through Chengdu. The narrator points out a number of the imaginary car's features, including a joystick controller, auto-pilot, and a collision-avoidance sensor. To add a bit of realism in one scene, a discarded can in the roadway rolls away from the car as it passes by.

Of course, for VW's hover car to work in practice, it would have to cost less to run than an ordinary car, and experts question whether that is possible in the foreseeable future. "You could argue that, because there's less friction, the hover car would be more efficient than fuel-powered vehicles with tires, brakes and other mechanism," says José Holguín-Veras, a professor of civil and environmental engineering at Rensselaer Polytechnic University. "I'm OK with that, but you're still going to need a rechargeable battery or some form of energy to power this vehicle, and the initial investment in a maglev infrastructure for the car would be substantial." The only vehicles that would benefit from such an infrastructure investment would be the hover cars themselves—wheeled vehicles running on combustion engines or batteries would still need well-maintained roads.

As imaginative as the VW hover car is, Holguín-Veras says, mass transit is still the best option for urban populations in the future as city populations swell and traffic congestion grows.

Perhaps the solution, then, isn't cars propelled along by electromagnetic energy but rather city buses that can make use of this technology. These could accommodate more passengers while providing greater coverage than maglev trains confined to specific guideways. Still, after seeing the video VW put together, who wouldn't want to take Jia's hover car for a spin?

Images and video courtesy of VW