Projects

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 stormwater 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. Change in historic designation for the 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 Re-evaluation #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, Fillmore 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.

Read Re-Evaluation No. 4


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 two-lane exit with two-lane deceleration.

Read Re-Evaluation No. 5


Re-Evaluation No. 6

Between Brighton Boulevard and Colorado Boulevard, there have been minor adjustments and refinements to the design of the Project. These changes have resulted from advanced design and include the following types of modifications: 

  • Construction limit adjustments to accommodate the movement of construction equipment and project improvements such as fencing, grading, access to noise walls, Intelligent Transportation Systems (ITS) infrastructure, drainage, and tie-ins for roadways, sidewalks, driveways, and alleys.
  • Details regarding construction activities and access requirements are now better understood, and the need for additional minor, temporary easements have been identified on the private property.

With a few exceptions, this re-evaluation addresses changes north of I-70. Changes south of I-70 will be addressed in re-evaluation #7.

Read Re-Evaluation No. 6


Re-Evaluation No. 7

Between I-25 and Colorado Boulevard, there have been minor adjustments and refinements to the design of the Project. These changes have resulted from advanced design and include the following types of modifications: 

  • Construction limit adjustments to accommodate the movement of construction equipment and project improvements such as fencing, grading, Intelligent Transportation Systems (ITS) infrastructure, drainage, and tie-ins for roadways, sidewalks, driveways, and alleys.
  • Details regarding construction activities and access requirements are now better understood, and the need for additional minor, temporary easements have been identified on private property.

With a few exceptions, this re-evaluation addresses changes south of I-70. Changes north of I-70 have been addressed in re-evaluation #6.


Re-Evaluation No. 8

Between I-25 and Chambers Road, there have been minor adjustments and refinements to the design of the Project. These changes have resulted from advanced design and include the following types of modifications:

  1. Modification of the construction limits to accommodate drainage as determined through coordination with the Union Pacific Railroad.
  2. The addition of a water quality pond determined through coordination with the City and County of Denver (CCD).
  3. Other minor design adjustments throughout the corridor to allow access for construction equipment and tie-ins between new sidewalks and existing parking lots.


Re-Evaluation No. 9

This re-evaluation assesses the impacts from one design alteration. At Peoria Street, just to the north of I-70, the construction limits will be extended to allow the existing roadside drainage ditch to be re-graded to flow into the existing culvert and drainage system.

In the pre-project condition, stormwater collects in the northeast quadrant of I-70 and Peoria Street and does not fully drain away into the stormwater collection system. To solve this problem the existing drainage ditch on the east side of Peoria Street will be re-graded to the point where it connects to an existing culvert that carries the stormwater to the west under Peoria Street. Also, the ditch on the west side of Peoria Street will be re-graded to carry the stormwater away and into the existing drainage system.

To accomplish this, construction work will extend approximately 155 feet beyond the existing construction limits established by the Record of Decision (ROD).  The construction limits extension is fully within the existing public Right-of-Way (ROW).


Re-Evaluation No. 10

Between I-25 and Colorado Boulevard, there have been minor adjustments and refinements to the design of the Project. These changes have results from advanced design and include the following type of modification: 

  1. Two existing sign bridges spanning I-70 need to be replaced with a single bridge spanning both directions of travel. 


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