Visions of the future have long revolved around the automobile, from the ubiquitous flying car of sci-fi flicks such as The Fifth Element to the garbage-guzzling, Mr. Fusion–retrofitted DeLorean that Doc Brown pilots through time in Back to the Future.

So a car company sponsoring a competition to dream up a vision of the future actually seems to make a lot of sense. The Audi Urban Future Award is a contest among six international architecture firms to envision futuristic cityscapes, circa 2030, with an emphasis on, ahem, personal transportation. ("Audi is confident that there will be cars in the city of the future," the competition Web site declares.)

The winner of the competition will not be announced until the 12th International Architecture Exhibition, which begins August 29 in Venice, but the firms met May 28 at a conference in London to present their preliminary concepts.

Some are fantastical, such as Standardarchitecture's vision for the future of Beijing, where the firm is based. The "harmonious Beijing" (pictured) is ringed by pillarlike buildings known as "metamountains"; the roads become conveyor belts that transport people around the city—whether on foot or inside Audi-branded pods.

The New York City–based firm of Diller Scofidio + Renfro imagined a future in which transportation and housing are more closely entwined. Riffing off the concept of the recreational vehicle, the architects proposed that in the future an increasingly mobile population may want to have a modular, portable personal space to bring along with them in the form of a shoebox-shaped modular unit. Audi could, according to the concept statement, "provide new ways of living, working and moving within the city beyond the categories of the car and the house." Buildings might become scaffolds, essentially, with slots to accommodate the units.

Other firms eschewed grand visions of the city to focus on the vehicle itself. Barcelona's Cloud 9 loosely conceived of a vehicle that is both light and flexible—a bubble with soft skin and photovoltaic dots that generate energy. The Bjarke Ingels Group of Copenhagen turned to the long-running fantasy of the driverless car, which in this case is also presumed to be clean-running. The firm's concept statement ponders how a city might look without traffic and automotive pollution but skirts the details, noting that foretelling the long-term future is a tricky business—witness the nonarrival of the flying car.

But what the heck? It's fun to prognosticate, and there's a cash prize. The award comes with an endowment of 100,000 Euros, or about $120,000—enough for two Audi A6s with a nice option package.

Standardarchitecture's "harmonious Beijing" conception used with permission from Audi AG