Conceptual design encompassed the Alternative Development and Screening processes and was crucial in determining how well a proposed alternative was able to meet the Purpose and Need of the project and what type and degree of environmental impacts were associated with it. It was during conceptual engineering that the alternatives were evaluated based on ability to correct existing roadway deficiencies as stated in the project Purpose and Need and to meet current highway design standards with minimal environmental impact. Alternatives that cannot meet these criteria were eliminated from the process and those that were determined to be reasonable were studied in greater depth.

Read more about the Purpose and Need on the Project Description page.

When feasible alternatives were identified for the various portions of the project, they were grouped into reasonable alternative packages fulfilled the overall project objectives. These packages, also known as "system alternatives", then underwent a final evaluation and comparison in order to select the final "Preferred Alternative" for the corridor. When the Preferred Alternative was selected, as much as 30% of the preliminary design work had been completed and the Preferred Alternative is ready to proceed into final design and then into construction.

Alternative Development and Screening
In the Fall of 2002, the Valley Highway project team in concert with the Technical Working Group developed a method to create and then screen alternatives for the Valley Highway EIS project. The alternative development and screening process included the following:

Development of Alternatives
Alternatives were developed with an emphasis on the "interchange nodes" along the corridor (I-25 interchanges with Broadway, Santa Fe, Alameda Ave. and 6th Ave., and 6th Avenue Interchanges with Bryant St., and Federal Blvd.). In addition, alternatives for the alignment of I-25 and alternatives for the grade separation of the railroad crossing at Kalamath/Santa Fe were developed. More than 80 alternatives were presented at the December 2002 Public Meetings.

The map below contains links to detailed information regarding the interchange and the I-25 mainline alternatives: Detailed Alternatives Map and Alternatives Information

Screening of Alternatives - Initial Screening for Reasonableness and Practicalbility
The project team first evaluated the relative merits of the alternatives by applying an Initial Screening for Reasonableness and Practicability. This resulted in the selection of 23 interchange alternatives and one I-25 mainline alternative.

The map below contains links to detailed information regarding the eliminated alternatives and a description of the reasons for elimination: Detailed Alternatives Map and Alternatives Information

Compatibility Testing
The remaining interchange alternatives were further evaluated with a Compatibility Testing step. This resulted in a further reduction of the alternatives to a group of 15.

The map below contains links to detailed information regarding the alternatives that were eliminated and a brief description as to why they were eliminated: Detailed Alternatives Map and Alternatives Information

Detailed Alternatives Map and Alternatives Information
Click a label to view detailed information regarding the alternatives.

System Alternatives Development
The remaining 15 interchange alternatives and the I-25 mainline alternative were packaged into “system alternatives". A system alternative is a combination of interchange and mainline alternatives that is able to fulfill the project Purpose and Need for the project corridor (I-25 from Logan St. to 6th Ave. and 6th Ave. from I-25 to Federal Blvd.). Four system alternatives were developed from 13 of the 15 remaining interchange alternatives and the I-25 mainline alternative. Additionally, the No Action Alternative, must be included in the EIS evaluation. These system alternatives were proposed to the public in July 2003 for review and comment. Building on comments received at that meeting and further consolidation of alternatives to achieve specific goals, four alternatives were advanced for more detailed environmental study in the Draft EIS.

The four system alternatives were as follows:



• System Alternative 1: Maximize Use of Existing Right of Way - this alternative best avoids or minimizes new right-of-way and impacts to environmental resources to create an environmentally sensitive alternative that utilizes the existing right-of-way to its fullest extent.

• System Alternative 2: Maximize Operational Performance / Safety - this alternative offers the best operational and safety benefits to create an operationally enhanced alternative.

• System Alternative 3: Maximize Facilitation of Local / Regional Plans - this alternative best meets the community plans relative to right-of-way impacts, bicycle/pedestrian mobility, land use planning, safety, and urban aesthetics. This alternative was developed with input from Denver, the Regional Transportation District, and the public through Citizen Workshops and public meetings.

• No-Action Alternative - this alternative includes only minor safety and maintenance improvements.

These alternatives were fully evaluated in the Draft EIS with regard to transportation benefits and environmental considerations.

Identification of the Preferred Alternative

In the Final EIS, CDOT and FHWA identified a Preferred Alternative for the Valley Highway Project that combines elements of the three system alternates 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)

Following identification of the major elements of the Preferred Alternative, CDOT and FHWA reviewed the elements in light of comments that had been received on the Draft EIS to establish whether any refinements should be made to the elements to address specific concerns. This resulted in a number of refinements being made to the Preferred Alternative, as follows:

Location	Refinement to Preferred Alternative	Reason for Refinement
I-25/Broadway	Retain signal and full movement operation at Broadway and Kentucky Avenue (instead of right-in right-out access)	Improved access to RTD station and park-n-Ride; avoids introduction of buses onto Exposition between Broadway and Lincoln St.
I-25/Alameda	Add auxiliary lane on westbound Alameda Avenue from Kalamath Street to northbound I-25 ramp	Improved operations
I-25/Alameda	Add auxiliary right turn lane on northbound Lipan Street at Alameda Avenue	Improved operations
Santa Fe/ Kalamath/ CML	Alignment refinements to Santa Fe Drive at CML and refinement of the bicycle/pedestrian bridge connection	To enhance constructability and local business access
US 6/Federal	Reposition braided ramp entrance to south side of combined ramp	Improved operations realized through easier weaving; ease of signing; and improved driver expectancy
US 6/Federal	Reconfiguration/reconstruction of Barnum East Park with the acquisition of additional property	To maintain and enhance park function to minimizes harm to the park

These refinements have been included in the Preferred Alternative as presented and analyzed in this Final EIS.

The Preferred Alternative balances transportation improvements with social and environmental considerations. CDOT and FHWA have concluded that the Preferred Alternative:

• meets the project purpose and need
• is feasible to build
• does not restrict consideration of alternatives for other reasonably foreseeable transportation improvements
• meets the long-term vision
• meets the needs or objectives of social, economic and environmental concerns
• is the Environmentally Preferable Alternative in accordance with CEQ
• is the Least Environmentally Damaging Practicable Alternative in accordance with Clean Water Act Guidelines [404(b)(1)]
• best avoids and/or minimize harm to Section 4(f) properties
• has general public acceptance

Design of the Final Preferred Alternative

As part of the NEPA EIS process, the Valley Highway EIS Study took into account other existing and planned transportation projects. To assure continuity with other ongoing planning efforts, the CDOT Project Manager met monthly with RTD, City and County of Denver, and DRCOG representatives about the Valley Highway Corridor and the need to coordinate actions and reduce impacts. CDOT also met regularly with representatives from Cherokee Denver and Gates to address the increase in traffic volumes expected from redevelopment of the Gates property.

Design and Technology - improving the national highway system

Click to read Design and Technology for information, insight and links to learn more about the ever improving design and safety standards of the national highway system. Read why reconstruction of older portions of the system is necessary, how design standards have advanced with advances in technology, and how information about system usage is used to make the system safer and more cost effective.

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