Low bid for SR-520 bridge $160 million less than projected budget

The low bid for the State Route 520 bridge came more than $160 million under the projected budget, the Washington State Department of Transportation said Wednesday. Kiewit-General-Manson’s bid price of $586.5 million for construction of a new, six-lane floating bridge is $163.5 million less than the upset price of $750 million included in the request for proposals. WSDOT staff analyzed and scored proposals from three prequalified teams vying to design and build the new bridge.

August 10, 2011 6:59 pm

The low bid for the State Route 520 bridge came more than $160 million under the projected budget, the Washington State Department of Transportation said Wednesday.

Kiewit-General-Manson’s bid price of $586.5 million for construction of a new, six-lane floating bridge is $163.5 million less than the high-end estimate of $750 million included in the request for proposals. WSDOT staff analyzed and scored proposals from three prequalified teams vying to design and build the new bridge.

“Replacing the aging SR 520 bridge is a critical priority for the state and an investment that will create jobs today and into the future,” Gov. Chris Gregoire said. “Identifying the contractor who provides the apparent best value is a major step toward constructing a safer bridge that will keep our economy moving.”

WSDOT plans to award and execute this combined contract for design and construction in the coming weeks, subject to final review and acceptance of the proposal.

Construction is scheduled to start on Lake Washington in 2012. WSDOT’s goal is to open the new bridge to traffic as soon as December 2014. The design-build contract includes:

• Building a six-lane floating bridge with wider, safer shoulders, a transit/HOV lane in each direction and a bicycle/pedestrian path.

• Towing 33 concrete pontoons to be built in Grays Harbor and assembling the floating bridge on Lake Washington.

• Building 44 supplemental concrete pontoons and 58 anchors.

• Building an east approach connection to the six-lane Eastside highway currently under construction and building a new maintenance facility and dock on the east shore of Lake Washington.

The team of Kiewit and General are experienced bridge constructors in Washington, having completed the Tacoma Narrows Bridge and the SR 104 Hood Canal Bridge. Kiewit-General is currently building pontoons in Aberdeen for the new SR 520 floating bridge. Manson Construction is experienced in heavy marine construction, and is currently working with WSDOT to replace the Manette Bridge. Kiewit-General-Manson will be supported by engineering firms KPFF and BergerABAM, both of which have a strong local presence.