The Denver Union Station Transit Improvements project transformed 42 acres of blighted former rail yards into the centerpiece of a bustling lower downtown neighborhood. It also anchors connections between the region's transit systems.

Pphoto courtesy of RTD
The signature design element of Denver Union Station is the SOM-designed white canopy above the main rail tracks.

Riders can now hop between bus, light rail or commuter rail via a new eight-track commuter rail train hall, a separate light rail station and an airy, airport-like 22-bay underground bus concourse. Street realignments and new public plazas set the stage for the mixed-use transformation of a former no-man's land in the Central Platte Valley.

"Bringing all those transportation modes together in a vibrant place is really cool," says Mark Imhoff, director of the Colorado Dept. of Transportation's Division of Transit and Rail.

The project is noteworthy for several reasons: At $374.8 million, Union Station is the most expensive multimodal project in the U.S., and, spanning 17 city blocks, it is also the largest transit project ever to seek LEED certification. The Kiewit-led design-build team worked with the city and the owner to transform their vision into a plan for the public-private partnership. Funding sources included two federal loans, federal and state grants and proceeds from land sales.

"The biggest takeaway from this project is that it proves that cities can deliver significant infrastructure projects that are also about creating a new neighborhood," says Kristopher Takacs, associate director and Union Station project manager for architect SOM, New York City. "And they can do that through public-private partnerships."

"The Union Station redevelopment was a complicated project with multiple funding sources, complex design challenges and a lot of properties and property owners," says Bill Mosher, senior managing director for Trammell Crow, Denver, the owner's representative. "But everybody played well in the sandbox."

The station's new bus facility is 1,100 ft long and 150 ft wide and sits 23 ft below grade. The bus-passenger concourse alone encompasses 44,000 sq ft. Because the facility was built below the area's water table, its exterior walls are 2 ft thick and the floor is 4 ft thick to keep it watertight.

The sheer size of the Union Station project created extraordinary safety issues. Mandatory orientations set the stage for the project's safety culture. A two-hour course on site-specific hazards was required before workers entered the jobsite. Other safety program elements included Kiewit's Speak Up, Listen Up program, near-miss reporting and ongoing job hazard analysis.

The JHAs reinforced preventative actions through planning and craft engagement and aimed to remove potential hazards from individual tasks. On a project that required more than 3.3 million man-hours to complete, workers practiced exceptional safety awareness. Throughout the four-year duration, the Kiewit team did not receive a single OSHA citation.

Denver Union Station Transit Improvements


Key Players


Owner's Rep Trammell Crow Co.

Master Developer Union Station Neighborhood Co. (East West & Continuum Partners)

Lead Architect Skidmore, Owings and Merrill LLP

Lead Design Firm AECOM

Public Realm Architect Hargreaves Associates

General Contractor Kiewit