State of the art transportation west of Denver used to mean saddling up a horse. But at the Jefferson County Fairgrounds Dec. 13, the public was given a look at what the future of travel up the I-70 corridor might look like.

The public tech expo was hosted by the Colorado Department of Transportation (CDOT) as part of the $1.8 million Advanced Guideway System (AGS) feasibility study.

The study has three phases, according to CDOT Special Projects Manager David Krutsinger. The first step is to gather proposals from around the world about what type of rail/guideway system might work in the Rockies. Second, CDOT will analyze what type of alignment those technical options require. Questions to be answered, Krutsinger said, include whether they could follow the freeway, and how much land would be needed for the tracks, and stations. Phase three will look at how to pay for the estimated $15 billion cost.

“Today’s forum is the culmination of our exploration of the first one,” Krutsinger said.

A total of 18 firms proposed their versions of a rail technology that could stretch from Denver International Airport to the Vail Airport, and carry people faster and more efficiently than another lane of asphalt.

The 40-member study commission compared the proposals using several key criteria, including safety, proven technology, capability even in wind and weather, and the ability to be operational as early as 2017.

Those criteria narrowed the field to proposals from 10 firms, and eight of those attended the expo.

Krutsinger said the public expo helped CDOT keep the public informed about the progress of the study and gather input from regional stakeholders. He said it was also just to share “the wow factor of seeing what these technologies are capable of.”

CDOT anticipates any new tram system becoming at least partially operational by 2025.

Among the expo attendees were some study commission members, along with city representatives for mountain communities, including Idaho Springs and Empire.

• American Maglev Transit of Powder Springs, Ga.: Magnetic levitation and linear induction of large passenger cars of approximately 200 passengers along with their luggage.

• Flight Rail of Ukiah, Calif.: A passenger tram along an elevated guideway, powered by vacuum air pressure built up in the pneumatic tube that the tram will ride above.

• General Atomics of San Diego and Colorado Maglev Group: Large guiderail tram proposal, designed in collaboration with the Federal Transit Administration. This system could carry standard truck containers.

• MegaRail of Fort Worth, Texas: A system that looks a bit like a raised motorway. Electrically powered, rubber-tire vehicles move freight and large passenger cars, while other users could drive their own vehicles onto flatbed cars for transit.

• PPRTC of Colorado Springs: A Personal Rapid Transit approach, with pod-cars that seat up to six, on a fixed guideway. Each pod car is elevated on a cushion of compressed air and propelled forward magnetically. Pods act as taxis, going directly to the desired stop. Each pod is fed power, generated through hydrogen fuel cells, at station stops.

• SkyTran of Longmont: Also a point-to-point service, using small three-seat pods to move passengers directly to their destinations. The pods hang below the guideway, and the system uses a magnetic, linear motor system for motion.

• Swift Tram of Boulder: Another hanging train design, it uses adjustable passenger compartments to move up to 38 passengers.

• Talgo of Seattle, Wash.: Possibly the most traditional proposal, Talgo trams would use energy from the power grid, traction motors and conventional adhesion. Regenerative braking, like that used on hybrid vehicles, would be used to minimize energy needs.