The following projects all involve ideas that originally came from science-fiction tales. However, many of the projects remain within the realm of possibility and some are on their way to reality. Stories that once made people dream are now sending engineers, contractors and lawyers to their respective tools to formulate proposals.

Tubular Rail

Railroads, which operate on standard gauge tracks, with set car sizes and turning radii, are not prone to major design changes. But Robert Pulliam has brought some fresh thinking to bear on this venerable transportation mode. For the past decade he has been presenting his concept for a “tubular rail” system that would eliminate rails.

He envisions 420-ft-long cars traveling up to 90 mph on elevated stanchions, 100 ft apart. The car bodies would be made of high-strength carbon fiber, and steel keel beams on the bottoms would make contact with and be propelled by motorized rollers on every stanchion. In terms of design criteria, "the idea is to maximize the span length and minimize the car weight," says Pulliam.

Because the stanchions would be elevated and use corridors alongside interstate highways or above city streets, "they would require easements, rather than rights-of-way," Pulliam explains.

Engineering assessments—carried out by graduate students at Dartmouth College's Thayer School of Engineering in 2006, 2007 and 2008—found the concept to be feasible. Pulliam claims the cost of building a tubular rail system would be $20 million per mile, which compares favorably with the costs of existing light-rail and monorail systems.

Next month Pulliam will be presenting his concept to the Exploratory Advanced Research Program of the Federal Highways Administration. “What we’d like is government support and funding of a demonstration project at the Pueblo facility in Colorado,” says Pulliam. [The Federal Railroad Administration’s test facility, operated by the Association of American Railroads.]

Vacuum-Tube Transport

Another rail rethink vying for governmental attention is vacuum-tube transport—that is, shooting transit capsules between cities or continents via evacuated tube systems at thousands of miles per hour.

"We're trying to prove design speeds," says Daryl Oster, president of Evacuated Tube Transport Technologies (ET3), who says he is in the middle of securing over three miles of federal land in the desert outside of Barstow, Calif., for a full-scale test. It requires a mile to speed up to 600 mph, a mile to coast and a mile to slow down. The ET3 concept is similar to Elon Musk's Hyperloop but with smaller-dia pipes and smaller cars that levitate atop magnetic tracks.

In Oster's design, 51-in.-dia, 400-lb cars would ship reclining passengers or wooden pallets around the world at a top speed of 4,000 mph. The idea is more like an electronic highway than a railway, in that many small capsules travel at once and determine when to enter or exit the tube.

Floating Cities

The New Orleans Arcology Habitat is a floating megastructure and the concept of Kevin Schopfer, a Boston-based architect. Designed to rest on a floating platform and be anchored offshore, the open tetrahedron is 1,200 ft tall and capable of serving 30,000 residents.