bnr-co-central-70-upgrades
  1. We are WSP
  2. What we do
  3. Projects
  4. Colorado’s Central 70 Upgrades

Colorado’s Central 70 Upgrades Connect and Enhance Communities in the Denver Metro

The landmark corridor improvement project connects and enhances communities in the Denver Metro Area.

Location

  • Denver, Colorado, USA

Project Value

  • $1.3 billion

Project Status

  • Complete

Colorado's largest highway infrastructure project in history, the Central 70 (C70) project is a $1.3 billion public-private partnership that involved reconstructing 10 miles of Interstate 70 (I-70) in a mixed industrial and residential area north of downtown Denver. The critical corridor sees 200,000 vehicles per day.

Improvements required removal of a 50-year-old viaduct structure, which carried I-70 through north Denver and had one of the lowest bridge ratings in the state. The project also relocated the existing highway below grade; added an additional express lane in each direction; constructed cross-street bridges between the communities on each side of I-70 with ADA compliant sidewalks; and most significantly, incorporates a four-acre “cover park” that now acts as a connector between the environmental justice neighborhoods of Elyria and Swansea.

Major project challenges included keeping the now subsurface I-70 highway profile above the groundwater table and providing the cover park with amenities and connections to the adjacent local streets and Swansea school, while maintaining vertical clearances to bridge crossings and the cover park. The design team also focused on providing crossings accessible for the physically challenged to improve safety and connectivity at all adjacent local streets in the project area, adjusting roadway and ramp profiles in an iterative process to accomplish ADA goals.

Demolition of the 2.5-mile viaduct was complete in three months with approximately 75 percent of the existing viaduct concrete was used during construction of the east bound lowered section.

The project included one of the first U.S. tunnels with fully integrated fixed fireproofing system and ventilation systems. The design incorporated a new precast, prestressed girder type for most of the highway bridges within the project, eliminating girder lines and reducing bridge profile and depth. Bridge girders forming the tunnel roof were designed with fire-resistant concrete, eliminating the need for fireproofing on the tunnel ceiling and reducing maintenance costs.

img-co-central-70-york-street-construction

Construction of York Street I-70 Bridge

The project required extensive community outreach and agency involvement to meet the needs of a culturally diverse area in Denver. The project team worked to engage the communities every step of the way during construction. A bilingual community liaison hosted office hours twice a week and offered home visits to discuss upcoming construction activities and resident issues.

Numerous aesthetic components were incorporated to represent the character of the neighborhood, like community-selected art patterns on the retaining and sound walls, consistent coloring and monuments on bridges, and public artwork selected by the community at the cover park.

Miles
10
New Bridges
18
Deckpark
4 acres
Affordable Housing Contribution
$2 million

Other challenges that we have overcome