City: Denver

AECOM led a joint venture, MKK Constructors, on Segment IV of E-470 – the remaining 12.5-mile, four-lane, controlled-access toll road that skirts the northern edge of the Denver, Colorado, metropolitan area.
The general roadway alignment of Segment IV traverses rolling high prairie terrain and farm ground irrigated by a series of canals and ditches. The roadway skirts several rural housing developments and crosses various streets, country roads, and the major transportation arteries of I-76, US 85, and the Union Pacific Railroad. Wetlands replacement was also included in the project scope. The project was completed five months early and $1.3 million under budget.

AECOM also performed the design-build contract for Segments II and III. Under a separate O&M contract, we operated Segment I of the toll way from 1992 to 1997. With the completion of Segment IV, the entire toll way is in service from I-25 in the north, around the eastern edge of Denver, and back to I-25 in the south, providing motorists with improved access to fast-growing suburban areas and the Denver International Airport. I Interstate 25 runs north and south through the middle of Denver.

Highlights and accomplishments for Segment IV include:

• A directional interchange with I-25
• Seven interchanges
• 43 bridges
• One mainline and eight ramp toll plazas
• Over 100 utility relocations
• 42 acres of wetlands creation and mitigation
• 415,000 tons of asphalt
• 233,000 square yards of concrete paving
• 10,600,000 cubic yards of earthwork
• State-of-the-art toll collection equipment

Since the 1980s, the city of Denver, Colorado, has metamorphosed from a blighted, declining city into one of the nation’s fastest-growing, economically attractive urban areas. This transformation was made possible by savvy real-estate investors, intuitive business entrepreneurs, local politicians, and socially conscious citizens.

As with any long-term civic revitalization programs, there were growing pains. One of Denver’s major concerns was how to best deal with the 120-year-old Union Station. This 9-square-block historic structure sits in the middle of several booming real estate markets, including Denver’s Lower Downtown district and the rapidly developing Central Platte Valley. Once an important hub of a vital regional transportation network, the neoclassical Union Station building faded into irrelevancy with the advents of automotive and air travel.

Where some saw an obstacle, wiser investors and community developers saw an opportunity. In 2006, AECOM, Kiewit, and SOM won the bid as master developer of Union Station and its 19.5-acre site. Decisions were made to not only renovate the station to accommodate the region’s modern transportation infrastructure and demands, but also to incorporate 1.35 million square feet of mixed-use development and public spaces.

AECOM worked hand-in-hand with its development partners, stakeholders and various community representatives to make this complex vision into an operating reality. AECOM was responsible for all aspects of transportation planning, and was appointed lead designer on the Kiewit design-build team that delivered the project’s $489 million multimodal transit component.

Details on each transportation mode include:

• Commuter Rail Train Hall — On the west side of the Historic Station, includes eight at-grade tracks to accommodate passenger rail service, including the northwest, east, north metro and gold commuter rail lines, as well as existing Amtrak and Ski Train services. Designed to handle as many as 10,000 people an hour, the train hall honors the historic station while providing a dramatic new gateway to the Mile High City.
• Regional Bus Facility — An expanded regional bus facility replacing Market Street Station is located below grade under the 17th Street right of way between the light rail platforms and the historic station. The bus facility includes 22 bays; 16 for regional and express buses, four for the downtown circulator, and two available for other commercial carriers or new services.
• Light Rail (LRT) Station/Platforms — LRT platforms have been relocated adjacent to the consolidated main line to accommodate west, southeast and southwest light rail service. Space has also been provided for tail tracks north of the platforms to store additional trains. A plaza between LRT and Chestnut Place includes a signature canopy to provide shade and weather protection.
• 16th Street Mall Shuttle — The free 16th Street Mall Shuttle, already a Denver icon, has been extended to a location adjacent to the new light rail platforms, connecting Civic Center to the Platte River. The shuttle provides easy connections for LRT, commuter rail, and regional bus passengers to reach their downtown destinations.
• Downtown Circulator — Building on the success of the 16th Street Mall Shuttle, the downtown circulator connects Denver Union Station to the employment centers in mid-downtown and continues to Civic Center on 18th/19th Streets and Lincoln/Broadway. The circulator provides service to passenger rail, regional bus and light rail riders via the underground regional bus facility.
• Historic Station — The historic station continues to have a prominent role in the new multimodal transit district. The train room has been rehabilitated to its historic prominence as a transportation gateway to Denver, connecting the east and west sides of the site.
• Public Spaces — The redevelopment includes several new significant public spaces, including the Wynkoop Plaza, the 17th Street Promenade/Gardens, the Wewatta Pavilion and the Light Rail Plaza. The public spaces create a series of interconnected places that tie the site together, allowing visitors to move from one destination to another.

Unique in many ways, the Denver Union Station project has showcased AECOM’s ability to create design solutions that reduce cost and increase quality, including:

• Use of precast materials — Reduces constructions schedule, improves quality and safety, improves integrity of structure/waterproofing, and reduces future maintenance costs.
• Construction staging — Minimizes impacts to transit and vehicle operations, maintains access to local businesses.
• High fly ash concrete — Improves quality of finish, reduces effects of heat and hydration during mass concrete construction and is a recycled material.
• BIM 3D modeling — Allows engineers to identify and resolve conflicts electronically, rather than during installation.
  Mat foundation design — Floating slab, four feet thick, that eliminates the need for deep foundations, reduces environmental impacts and saves time.
• Blind-side waterproofing — Eliminates the need for permanent dewatering and treatment.
  Pre-cast beam unistrut — Installed in bean bottom flange to expedite bean casting and allow for flexibility in the location and support of conduits and pipes.
  Innovative air ducts — Voids between box beams were used as air ducts to save valuable space and reduce schedule duration.
  The rehabilitated station and its surrounding complex represent a multimodal transportation hub unprecedented in scope that will undoubtedly become a focal point of activity in the heart of one of the nation’s busiest, most dynamic urban centers.

Awards

• 2014 Project of the Year, Design-Build Institute of America
• Transportation, National Award of Merit, Design-Build Institute of America
• Best Project, Airport/Transit and Safety, ENR Mountain States, 2014