Frequently Asked Questions


The Project is designed to improve the safety, mobility and community connections along one of Colorado's most congested interstate segments. It will bring the first infrastructure improvements to I-70 since this stretch of interstate was opened to traffic in 1964. Since then, usage of this highway has skyrocketed to nearly 200,000 vehicles daily. This project will include:

  • The addition of one new Express Lane in each direction from I-25 to Chambers Road.
  • Removal of the 55-year-old viaduct and lowering of the interstate between Brighton and Colorado Boulevards.
  • Construction of a new, 4-acre park over the interstate between Clayton and Columbine streets that is modeled after similar, successful public spaces over highways across the nation. CDOT is working closely with the City and County of Denver and local residents to design an active, thriving, year-round space to connect the neighborhood.
  • Project mitigations such as support for new low-income housing development and significant improvements to Swansea Elementary School.

The purpose of the Project is to implement a transportation solution that improves safety, access and mobility, and addresses congestion on I-70.

The need for this Project results from the following issues:

  • Increased transportation demand
  • Limited transportation capacity
  • Safety concerns
  • Transportation infrastructure deficiencies

  • Reduced congestion and improved reliability on Denver’s most significant east-west corridor
  • Increase in Denver’s attractiveness as a place to do business
  • Aging infrastructure brought up to modern engineering standards

Construction began in September 2018, with construction scheduled for completion at the end of 2022.

This project will cost $1.2 Billion, with contributions from Colorado Bridge Enterprise, Senate Bill 228, Denver Regional Council of Governments (DRCOG) and the City and County of Denver

  • Viaduct remains in place until 2020
  • Three lanes open in each direction on I-70 during daytime hours
  • Limited number of full closures and major traffic switches on I-70
  • Programs/incentives to encourage carpooling and transit use
  • Coordinated on-ramp and cross street closures to maintain access

The park was a request of the neighborhood and is one of the many mitigations provided by the Project. The 4-acre park over the highway that will connect the Elyria-Swansea neighborhoods that were divided when the viaduct was built in the 1960s.

Yes, Kiewit Meridiam Partners and CDOT have teamed up for this Project. KMP will operate and maintain the highway for 30 years once the Project is completed. However, The High Performance Transportation Enterprise (HPTE) will set the toll rates based on keeping the right amount of vehicles in the Express Lanes so travel times are reliable and CDOT will keep the tolls.

Express Lanes & Tolling

Adding an Express Lane can provide a level of travel reliability that a new general-purpose lane cannot; traffic on an Express Lane can be managed so vehicles are moving efficiently. Express Lanes on other highly traveled corridors in the state have proven to be successful in increasing roadway capacity, managing congestion, and providing travel choices, a reliable trip and improving travel times across all lanes.

To use any Colorado Express Lanes, you will need an ExpressToll account and pass to avoid a higher license plate toll. The Switchable HOV Transponder is the only pass that allows you to choose the carpool option and use the lanes for free if the driver has two or more passengers. Motorists can get a pass by visiting

Tolls will be determined as the Project nears completion.

Toll revenues will pay for the tolling equipment and installation, tolling operations and maintenance of the Express Lanes in the I-70 corridor to include snow plowing, debris removal and pavement repairs.

Travel Impacts

Decreasing traffic impacts is a top priority for CDOT. During construction, three lanes of traffic will be maintained in each direction during daytime hours and peak travel times the vast majority of the time. Most lane and ramp closures will occur overnight, during non-rush times. Drivers will notice that lanes will be narrower and the interstate speed limit will be reduced.

During construction, motorists using the corridor may experience more delays than normal. Please check the latest information on road conditions before heading out. If necessary, allow some extra time to reach your destination.

During construction, drivers are asked to stay on I-70, and avoid using local streets to bypass construction. You will not save time by detouring to local roads.

There will be utility work, ramp reconstruction and other construction activities that periodically affect roads connecting to I-70, but the bulk of the work is being done within the highway corridor. Highway lanes will be kept open during peak travel times to encourage drivers to stay on I-70 in lieu of seeking off-corridor detours, and with other local road improvement projects occurring simultaneously on some of the side streets, drivers will quickly learn that travel times won’t improve by avoiding the highway.

Interstate lane closures will be limited to nights and off-peak travel times whenever possible. A regular Safety Patrol will help move impaired vehicles quickly.

The Project team will coordinate with major events in the area and region, and work around-the-clock and on weekends (when needed) to deliver this project on time, on budget and with as few impacts as possible.

Environmental Protections

Has CDOT fully examined impacts on air quality as a result of the project? Yes, CDOT conducted a comprehensive analysis of the air quality impacts of the Central 70 Project following guidance and protocols set by the US Environmental Protection Agency (EPA) and the Colorado Department of Public Health and Environment. This work, which accounts for the growth in traffic through the year 2040, has shown that the Project meets all national health-based air quality standards set by EPA. CDOT would not have received Federal approval for the Project without making this determination.

CDOT has provided an unprecedented level of public involvement tailored specifically to communities adjacent to I-70 in order to find ways to improve the project and lessen its impacts. Through this process, the following specific and innovative commitments were developed:

  • Lowering the highway and providing a park with urban landscape adjacent to Swansea Elementary School.
  • Providing residents close to the highway construction with storm windows, furnace filters, attic insulation and two free portable or window-mounted air conditioning units
  • Providing $100,000 to facilitate access to fresh food
  • Providing an HVAC system and new doors and windows for Swansea Elementary School, plus two new additional classrooms
  • Providing $2 million in funding to support affordable housing in the Elyria-Swansea Neighborhood
  • Providing eligible residents of Globeville, Elyria and Swansea with free transponders, pre-loading of tolls or other means to reduce barriers to using the Express Lanes after the project is completed


Yes, CDOT has examined options that would reroute portions of I-70 at many different junctures over the 14- year study process. The concept of entirely moving a section of interstate that serves hundreds of thousands of commuters and freight vehicles every day is not a reasonable alternative nor is it one that would benefit local communities. At an estimated $3.2 billion cost, a reroute would result in significant traffic increases to the local street network and the construction of a major six-lane boulevard through Elyria and Swansea that would need to serve some of the region’s largest freight distribution centers.

Traffic forecasting for the Central 70 Project was done using the 2035 Denver Regional Council of Governments (DRCOG) trip-based travel demand model, which is the latest Compass model released by DRCOG. Compass is a regional model that applies projected land use data, including population and employment growth, to project future traffic conditions. This model incorporates household and employment data for the region and accounts for roadway and transit projects, including RTD’s commuter rail line (the A Line).

DRCOG owns and maintains this regional base model that incorporates every municipality within the DRCOG region, which includes the nine counties of Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson and the southwest portion of Weld County. Each alternative considered in the Final EIS was incorporated into DRCOG’s base model to determine future travel forecasts within the study area. These projections were used to determine the number of lanes needed for each alternative to accommodate future traffic growth.

In the more than 15 years spent planning this project, the Colorado Department of Transportation and Federal Highway Administration looked into several alignment options for I-70 between I-25 and Tower Road. These alternatives, presented and refined during a series of public meetings and hearings, included several general purpose and managed lane options for the section of highway between Brighton and Colorado boulevards along with options for rebuilding the viaduct in this section or removing it altogether and building I-70 below grade. This process yielded the preferred alternative – the partial cover lowered alternative – as the one with the most public support, the best in terms of improving safety and mobility, and the one that would restore and enhance the community while allowing Swansea Elementary to remain in its current location.

During the Environmental Impacts Statement process, intense study was done on the corridor between I-25 and Tower Road. However, there remains a gap between the estimated cost of the project and the revenue available to build it. Because of these funding limitations, the project will be constructed in phases over time. While the ability to define phases was not a factor in the identification of the Preferred Alternative, Build Alternatives were defined which could be implemented using a phased approach, with each phase contributing to the overall project purpose and need. The process—including the preparation of a ROD for each project phase—will be repeated until construction of the entire Preferred Alternative is completed. This approach serves as an enhancement to the typical NEPA process because it allows for future discussion of project phasing and only what is included in the Fiscally Constrained Regional Transportation Plan (RTP) can be approved in the ROD. Future phases, referred to as Phase 2, have not been determined. Phase 2 will rely on future funding and may be constructed in one or more construction packages. In general, Phase 2 incorporates the following portions of the Preferred Alternative:

  • Striping an additional tolled express lane from Brighton Boulevard to Quebec Street. Phase 1 constructed this section of I-70 wide enough to accommodate the additional lane.
  • Widen I-70 for an additional single lane in each direction, from Quebec Street to Chambers Road.
  • Widening to accommodate additional lanes and increase capacity from Chambers Road to Tower Road. Additionally, three direct connections are included from the tolled express lanes to I-270, I-225, and Pena Boulevard to accommodate regional and airport traffic. The direct connections result in a shift of eastbound I-70 to create room for the connections.


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