Central 70 Project Re-Evaluations

Re-Evaluation No. 1

This re-evaluation assesses the impacts of three categories of design alterations:

  1. Modification to the construction limits determined through coordination with the Union Pacific Railroad (UPRR);
  2. Changes to the off-site drainage system for the Central 70 Project due to anticipated reduction of storm water flow volume; and
  3. Other miscellaneous and slight design adjustments throughout the corridor completed to advance the project.

Re-Evaluation No. 2

This re-evaluation assesses the impacts of three categories of design alterations:
  1. Changes to fence line adjacent to UPRR at Ralston Purina Plant/Nestlé Purina Petcare Company
  2. Changes to easements adjacent to UPRR at 4790 Josephine Street
  3. Change in historic designation for property at 4637 Claude Court

Re-Evaluation No. 3

This re-evaluation assesses the impacts of two categories of design alterations:
  1. Construction limit adjustments to allow for additional space to facilitate movement of construction equipment and to tie-back slopes along driveway approaches.
  2. Minor adjustments to right-of-way (ROW) acquisition boundaries. ROW needs have generally been reduced through advanced design. This included refining design of ramp and frontage road geometry, and modifying design from a combination sidewalk/tree lawn section to attached sidewalks. However, ROW acquisition would increase on one parcel to accommodate an 8-foot sidewalk rather than a 5-foot sidewalk.

Re-Evaluation No. 4

Through the procurement process, the proposers were allowed to propose Alternative Technical Concepts (ATCs) for ways that would improve the project. This re-evaluation covers the changes proposed through the ATC process and included in this project that change impacts or modify the alternative selected in the ROD, except ATC 11.2, which will be covered in a future re-evaluation. 

ATC 12.2 – This ATC will eliminate the 72-inch storm sewer bridge over I-70 mainline by connecting to the Offsite Outfall System that was previously identified in Reevaluation #1 dated 9/18/17.

ATC 14.2 - Modify the I-70 typical section to allow for independent profiles of WB and EB traffic shifting the axis of the rotation/pivot point for superelevation, reducing the height of the retaining walls.

ATC 18.1 - Modify the normal crown cross slope design criteria of 2% with a centerline crown for the cross-street bridges at York Street, Josephine Street, Columbine Street, Clayton Street, Fil l more Street, Steele Street, Cook Street, Monroe Street, and Colorado Boulevard over I-70 through the Lowered Section and raise the profile of I-70 mainline approximately 6 to 12 inches.

ATC 28.1 - Reduce the inside shoulder width from 9 ft. to 6 ft. on the I-270 flyover bridge while maintaining the required horizontal stopping sight distance (HSSD) for the traveling public along I-270 by flattening the radius of 2,184 ft. to a radius of 2,590 ft.

ATC 68.0 - Modify the Onsite Outfall system to optimize the existing right-of-way and existing drainage infrastructure and eliminate the north outfall included in the ROD.

Re-Evaluation No. 5

1. Between Quebec Street and I-225, there have been minor adjustments and refinements to the design of the Preferred Alternative, Phase 1. The changes resulted from advanced design.

2. Between Dahlia Street and Quebec Street, there have been minor adjustments and refinements to the design of the Preferred Alternative, Phase 1 at selected side streets.

3. Between I-25 and Colorado Boulevard, Alternative Technical Concept (ATC) 11.2 has optimized the final design.

4. The proposed design and reconstruction of the interchange includes upgrading the I-70 westbound exit ramp to Quebec Street from its existing configuration as a single lane exit to a proposed a two-lane exit with two-lane deceleration.


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