Project Location Map      (click to view enlargement) The I-25 Valley Highway EIS project is located on I-25 between Logan Street and 6th Avenue.

Preferred Alternative
FHWA and CDOT have identified a Preferred Alternative for the I-25 Valley Highway Project that combines elements of the three system alternatives that were analyzed in the Draft EIS. The Preferred Alternative does not represent a new alternative, but rather a refinement based in the analysis contained in the Draft EIS and comments received from the public and agencies.

The Preferred Alternative includes the following major elements:

• I-25 Mainline: Widening of I-25 to provide a consistent section with four through lanes plus auxiliary lanes in each direction through the project area (these improvements were common to System Alternatives 1,2, and 3 in the Draft EIS)
• I-25/Broadway: Tight diamond interchange (these improvements were included in System Alternative 3 in the Draft EIS)
• I-25/Sante Fe Drive: Single point urban interchange with a flyover ramp for northbound Santa Fe Drive to northbound I-25 (these improvements were common to System Alternatives 1,2, and 3 in the Draft EIS)
• I-25/Alameda/Santa Fe/Kalamath: Offset partial urban interchange at I-25 and Alameda Avenue; Santa Fe Drive and Kalamath Street grade separated under the railroad close to their current alignments (these improvements were included in System Alternative 1 in the Draft EIS)
• US 6: Ramp improvements at the I-25/US 6 interchange; Closure of the Bryant Street interchange; Diamond interchange at US 6/ Federal Boulevard with slip ramps to Bryant Street and a braided ramp from Federal Boulevard to eastbound US 6; reconstruction of US 6 with collector-distributor roads/auxiliary lanes through the project area (these improvements were included in System Alternative 2 in the Draft EIS)

Lead & Cooperating Agencies
The Draft and Final EIS and the Phased ROD were prepared by the FHWA (as the Lead Agency) in partnership with CDOT (as the Applicant Agency). In addition, many local, state and Federal agencies participated in the process as cooperating agencies. The following Cooperating Agencies agreed to participate:

• City and County of Denver (CCD)
• Regional Transportation District (RTD)
• Federal Transit Authority (FTA)
• Federal Railroad Administration (FRA)

I-25 Valley Highway EIS     National Importance     (click to view enlargement) This project is located along I-25, a corridor of national significance.

Purpose and Need
The purpose of the Valley Highway Project is to:

• Provide lane continuity and balance on I-25 from Logan Street to US 6, linking with sections of I-25 to the north and south
• Optimize highway system operations while recognizing the constraints on highway expansion identified through the regional transportation planning process
• Improve connectivity between transportation modes
• Improve pedestrian/bicycle mobility across the project corridor
• Increase safety along and across the corridor for motorists, pedestrians, and bicyclists
• Correct roadway deficiencies along I-25 and US 6 to meet current design standards to provide a safer, more efficient, and more reliable transportation system
• Increase safety and reduce congestion and delays related to the at-grade crossing of Santa Fe Drive / Kalamath Street and the Consolidated Main Line (CML) railroad

The need for the project arose primarily out of a number of identified roadway deficiencies that result in unsafe conditions. The age, condition, and geometric design of the roadway compromise the safety of the traveling public and require improvements to meet current design and safety standards.

Project objectives have been established based on identified needs and a series of discussions with cooperating agencies, resource agencies, and the public.

Specific project needs and objectives fall into several categories as follows.

System Linkages / Lane Continuity and Balance:
• Need: Completion of the T-REX Project and I-25 / Broadway viaduct Replacement Project to the south will result in a discontinuity of travel lanes on I-25 through the project area, with four lanes in each direction to the north and south and three lanes in each direction through a portion of the project area.
• Objective: Provide lane continuity and balance on I-25 between the existing and planned roadway sections to the north and south of the project.

Transportation Demand and Operations:

• Need: The I-25 corridor is currently experiencing pervasive severe congestion, which is expected to continue to worsen.
• Objective: Optimize highway system operations as measured in reduced delay of vehicle hours/day, reduced hours of congestion, and/or levels of service.

Inter-modal Relationships and Bicycle / Pedestrian Mobility:

• Need: The I-25 corridor restricts east-west mobility for pedestrians and bicyclists and limits access to transit facilities.
• Objective: Preserve existing or provide improved facilities for automobile, bus, and pedestrian connections. Upgrade bicycle/pedestrian facilities within and across the project corridor to provide improved access to the Platte River Trail, safer facilities at intersections, complete missing links of bicycle/pedestrian facilities, and provide better linkages between transportation modes.

Safety:

• Need: Accident histories for I-25 and US 6 show greater accident frequency and severity than expected for similar facilities, due to congestion, close interchange spacing, and substandard geometric configuration.
• Objective: Increase safety and decrease the likelihood of accidents within the project corridor by improving the geometric design of the roadway system.

Roadway Deficiencies:

• Need: I-25 and associated interchanges have substandard geometrics and design features and many roadway structures are nearing the end of their useable life.
• Objective: Address existing roadway deficiencies, and replace aging structures to provide for improved operation of and reduced maintenance costs for the roadway facilities.

Consolidated Main Line Railroad Crossing at Santa Fe Drive and Kalamath Street:

• Need: Santa Fe Drive and Kalamath Streets cross the Consolidated Main Line railroad at-grade, causing congestion and safety concerns.
• Objective: Reduce system disruptions, and improve safety conditions related to the current at-grade crossing.

The following subsections provide a brief history of the project including a description of the existing conditions, discussion of corridor characteristics and a summary of the roadway design deficiencies, which ultimately result in the proposed action for this project.

Valley Highway History
What was originally built in Denver was not I-25, but the Valley Highway. It was completed in sections from north to south. All 11 miles of the route (from 58th Ave. to Evans Ave.) opened for traffic on November 23, 1958. It was initially built to four lanes and quickly reached capacity. Contingencies were built into the right-of-way to allow for six lanes, but the Colorado Department of Highways (CDH), at the time, could not afford to build all six.

Historical photos used courtesy of CDOT Library.  

Project Development
The Colorado Department of Transportation (CDOT) has long considered this portion of I-25 as a priority for study and eventual reconstruction. The poor condition of the existing viaduct from Broadway to Santa Fe, as well as the substandard geometry posed by the closely spaced interchanges from Broadway to Alameda, was a primary motivation for the CDOT to embark on a Feasibility Study in 1998 to evaluate the corridor.

			Read more about the history of the Broadway Viaduct Replacement project:
			Nov. 8, 2001 CDOT Press Release
			August 2002 Newsletter
			Read about the Design of the new Broadway Viaduct on the Construction page.
			Read more about the Construction of the Construction.

During a regular bridge inspection in 2000, the CDOT recognized that the viaduct was deteriorating more quickly than previously noted. They immediately began a program to design and secure funding to replace the viaduct. The project was evaluated and environmentally cleared and initial reconstruction began in the fall of 2001. A program is currently in place to replace the viaduct in phases to keep traffic moving and match funding as it becomes available.

Early in defining the project, it became apparent that there was the potential for significant environmental impacts associated with reconstruction of I-25. The FHWA, in partnership with CDOT, determined that an EIS was the appropriate NEPA process to adequately evaluate and resolve these impacts. The EIS was initiated in July 23, 2002.

Existing Conditions
The following graphics offer a brief overview of the existing conditions relative to accidents, traffic, and geometric deficiencies.

Accidents - we need to improve safety:

Accidents (click to view enlargement)

Traffic - we need to manage the traffic flow:

Existing Traffic Volumes (click to view enlargement)

The Denver Regional Council of Government's (DRCOG) 2025 regional travel demand model was used to establish future traffic volumes and patterns. This information is represented in the attached graphic in much the same fashion as the existing conditions. It appears that traffic will grow approximately 10-20% in the next 20 years on freeway segments. Growth projections on arterial streets range from no growth to 50% growth in some locations. Generally traffic will use the highway and city streets in much the same fashion as they do today - if no action is taken to change it. The project will incorporate revisions as DRCOG establishes new projections.

Year 2025 Traffic Volumes (click to view enlargement)

The Bottleneck:

Corridor Geometric Deficiencies - we need to eliminate corridor deficiencies:

Mainline I-25 Geometric Deficiencies   (click to view enlargement)

I-25/Santa Fe Interchange Geometric Deficiencies (click to view enlargement)		I-25/Broadway Interchange Geometric Deficiencies (click to view enlargement)

I-25/Alameda Avenue Interchange Geometric Deficiencies (click to view enlargement)		I-25/6th Avenue Interchange Geometric Deficiencies (click to view enlargement)

Project Funding

Due to current funding limitations and the requirements for fiscal-constraint, only Phases 1 and 2 as identified in the Final EIS, have been selected for implementation. Subsequent project phases will be selected and implemented as additional funding become available, enabling CDOT and FHWA to work toward implementation of the entire Preferred Alternative. For each subsequent phase, a ROD will be issued detailing the phase to be implemented. CDOT and FHWA will review the information provided in the Final EIS and the current ROD in preparing each subsequent ROD.

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