The SR 520 West Approach Bridge North project is a 1.2-mile-long bridge that connects the new SR 520 floating bridge to Seattle via the Montlake interchange. The bridge is mostly constructed through a shallow water area that requires the use of more than a mile of trestle to be installed. The hollow columns supporting the existing approach bridge are vulnerable to earthquake, and its four-lane roadway has narrow shoulders and no transit/HOV lanes or bicycle/pedestrian path.
What makes it interesting?
Flatiron’s winning bid of $199.5 million is the largest bid-build project in Washington State Department of Transportation history. While funding is not yet available to bid the south (eastbound) portion of the approach, the north portion will have the width to support four lanes of traffic in an interim configuration.
How HCSS Software assisted with this project
Three distinct Flatiron estimating departments throughout the West Coast were able to collaborate in a single estimate. Flatiron was also incorporate estimate information from its exclusive marine partner, Pacific Pile and Marine.