By Tasha Anderson for AZBEX
The City of Flagstaff has issued a Request for Qualifications for a firm to provide Design-Build services for the design and construction of an overpass in central Flagstaff.
According to the issued RFQ, the city is looking for services including, project design, agency/public coordination, budget control/value engineering and construction services.
The project, called the Lone Tree Overpass Project, will be a bridge overpass that will be an extension of the existing Lone Tree Road, from Butler Avenue to Route 66.
According to the documents associated with the RFQ, an alternatives study was completed in 2010 the city had three alternatives to choose from:
- Alternative 1 – North Alignment – Relocates the railroad tracks on the north side of the existing tracks and allows for four horizontal curves and three vertical curves including a sag curve under the bridge. Construction of a retaining wall and temporary shoring for railroad construction is required.
- Alternative 2 – South Alignment – relocates the railroad tracks on the south side of the existing tracks and allows for three horizontal curves and three vertical curves including a sag curve under the bridge. Construction of a retaining wall and temporary shoring for railroad construction is required.
- Alternative 3 – South Alignment with Shoofly – relocates Main 1 and Main 2 to shoofly tracks using the horizontal alignment of Alternative 1 while constructing the new mainline tracks on the horizontal and vertical alignment of Alternative 2.
The city chose Alternative 3, “to reduce the length of shoring between new construction and existing tracks and to facilitate construction of the overpass structure.”
“A portion of the Lone Tree Corridor from Sawmill Road to Butler Avenue will also be included in this effort for design and construction.”
According to the RFQ, in order to be eligible for consideration, firms must, “submit an SOQ demonstrating appropriate competence, qualifications, and relevant construction experience with these types of projects.” The chosen Design-Build firm will take the lead in the design phase and will hold the construction contract.
The estimated construction valuation for the Lone Tree Overpass Project is $52M; however, the RFQ states the actual budget will be determined during the design phase. The project was on the City of Flagstaff’s Capital Improvement Program for FY2019/20 through FY2023/24 and has an allocated amount of $16.4M. According to the CIP, that funding was provided through voter approval of Proposition 420 in November 2018. The current Capital Improvement program has not yet been issued.
No construction timeline has been set; however, the city expects the project to be completed prior to 2026.