The Minnesota and Wisconsin departments of Transportation have identified Ames/Lunda Joint Venture as the apparent low bidder to lead construction of the St. Croix Crossing bridge superstructure contract. MnDOT says it will closely review the selected bid to ensure the contractor meets specifications.
Ames/Lunda’s $380 million bid includes a price component and a time component — called A + B bidding. Each component is confidential until the project is awarded later in November. MnDOT and WisDOT pay the contractor the price component. The time component includes the number of days the contractor bids to complete the project, which gets assigned a dollar value.
MnDOT and WisDOT will evaluate the bids and work with the Federal Highway Administration to certify the bids.
The extradosed-type bridge design was selected by a community stakeholder group. Other construction in this contract includes:
• Ramp bridge from Highway 95 to the river crossing (south of main bridge)
• Ramp bridge from the river crossing to Highway 95 (north of main bridge)
• Highway 36 box girder approach bridge
• Connecting structure between the river bridge and the Highway 36 approach bridge
The extradosed bridge design is a hybrid of a concrete box girder structure — like the I-35W St. Anthony Falls Bridge in Minneapolis — and a cable-stayed structure — like the Golden Gate Bridge in San Francisco. It is lower in height than a typical cable-stayed bridge. The bridge design minimizes environmental impacts by keeping tower heights below the river bluffs and reducing the number of piers in the river to five. When completed, the St. Croix Crossing will be the second extradosed bridge in the United States; the first extradosed bridge is in Connecticut.
Construction will take approximately three years to complete, with the St. Croix Crossing opening to traffic in fall 2016.
The bridge is a part of the larger St. Croix Crossing project, which includes seven miles of expressways on either side of the bridge in Minnesota and Wisconsin. The project also includes an extensive trail facility for pedestrians and bicyclists, as well as historic and environmental mitigation efforts.