Construction is well along on the third and final phase of the sprawling $500-million effort to transform Denver Union Station into a multimodal transportation hub for the Mountain West region. Contractors expect to finish the project in about a year.

The Union Station design-build project, which stretches over 40 acres in downtown Denver's Central Platte Valley, is being done under the aegis of the Denver Union Station Project Authority as owner. The redevelopment is part of metro Denver's multibillion-dollar FasTracks transit project, one of the largest and most complex U.S. transportation programs. FasTracks, which involves expanding bus routes and rail lines, is set to continue for another three decades.

"The Union Station redevelopment is a complicated project with multiple funding sources … complex design challenges and mixing a lot of properties and property owners," says Bill Mosher, senior managing director for Trammell Crow Co., Denver, owner's representative for the entire project. "But everybody plays well in the sandbox." Funding sources are also varied, including two federal loans, federal and state grants and proceeds from land sales.

"I don't think people realize yet what this intermodal hub is going to mean for the city and the state," says Mark Imhoff, director of the Colorado Dept. of Transportation's Division of Transit and Rail and an authority board member. "Bringing all those transportation modes together in a real vibrant place is really cool. It makes us feel like a real city."

Union Station's transit component involves construction of an underground regional bus facility with 22 bays, an eight-track commuter rail hall with five platforms, relocation of an existing light rail station, laying track, significant landscaping and improvements to surrounding streets.

Construction began in early 2010, with delivery set for April 2014. Amtrak will move from its temporary onsite space into the terminal by next January. "Primary activities remaining are finishes of the bus facility, including build-out of the concourse," says Mosher, a veteran Denver developer. "Then we do the commuter rail component, which comes in over the bus facility."

Public Spaces

Public spaces such as plazas and pedestrian connections also must be finished. "We're spending $32 million on public improvements—brick finishes, lighting, granite seating benches, lots of trees and planters shaped like teardrops that channel the flow of people from trains," says Chet Haptonstall, Union Station project manager for Omaha-based Kiewit Corp., the transit component's general contractor.

"We've upgraded materials when we could, going from concrete pavers to granite in some cases," Mosher says. "That's where the recession has helped us. We're getting good bang for our buck."

Kiewit Infrastructure Co. leads the transit component's design-build team, working with other corporate units Kiewit Building Group and Mass. Electric Construction Co. Kiewit recently had more than 200 workers on the transit project. The building group is also constructing the five-story, 110,000-sq-ft One Union Station office building on the station's south side, to be anchored by the new headquarters of Denver-based energy firm Antero Resources.

Kiewit teamed up with architects Skidmore, Owings & Merrill (SOM), which drafted the master plan and then became project architect and engineer; transportation construction specialist AECOM Technology Corp.; and landscape architect Hargreaves Associates.

Contractors are pursuing LEED certification for the project, working with the U.S. Green Building Council to create a LEED designation for a transit complex.

According to Kiewit, remaining work at the underground bus facility includes interior finishes such as placing yellow glass wall tiles; laying terrazzo stone floors; finishing elevators and escalators; and installing cabling in the communications data room.