•  2003 Project Highlights
•  Evaluation Criteria

SR 20 - Methow River Bridge Replacement

Okanogan County

Design: Construction Management: Schedule: Cost: Engineers Estimate: $2,033,871.22 Contract Award Amount: $3,910,163.80 Estimated cost for completion: $4,060,000 Minor design issues were encountered during the construction process, most of which would have been difficult to resolve at the time of design. The contract team partnered together with good communication, proactively addressing issues and obtaining resolution. Several minor construction changes impacted the original scheduled completion date.  Completion was not pushed into another construction season, but the public was inconvenienced for a longer period than planned. The engineer’s estimate was substantially below the contractor’s bid amount. The super girder design cost was significantly underestimated at the design stage, causing a major and significant overrun.

This project is at the southern end of the town of Twisp where SR 20 crosses the Methow River in Okanogan County. The project replaced a narrow 1930s bridge, having two l0-foot wide lanes and no shoulders, with a new bridge that has two 12-foot lanes, 8-foot shoulders and a 6-foot barrier separated pedestrian sidewalk. The project improves safety and traffic flow for vehicles and pedestrians. The new bridge was constructed using “super girder” technology, which reduced the number of piers in the river from five to just one, making the bridge more environmentally friendly and easier to maintain. Transporting the super girders was an accomplishment within its own right, being almost 200 feet in length and weighing nearly 200,000 pounds each.

Construction Summary

The project began in July of 2001 and was completed September 2003. The contract went according to plan and lasted three construction season.  This was due to limited work allowed during critical, fish-sensitive time periods and winter work shutdowns.

The first half of the new bridge was started in first season and completed during second season. It was opened to signalized one-lane traffic while the old bridge was removed and the second half of the bridge was started. The new bridge was opened to two-way traffic in July 2003 and completely finished in September 2003. The contractor and WSDOT worked as a team throughout the project. The public was kept informed during the project by newspaper articles, radio interviews, and changeable message signs. The Town of Twisp personnel were kept abreast of the contract progress and issues, and were instrumental in working out coordination issues to ensure construction had minimal impact on the community. The contractor held a ribbon cutting ceremony on August 4th, 2003 celebrating the completion of the project and hosted a picnic to thank the public and dignitaries for their patience and cooperation.

Contractor:
One Way Construction Co. Inc., Sedro Woolley, WA.

WSDOT Contact:
Terry Mattson, Project Engineer
Phone:509-667-2860
E-mail: mattsot@wsdot.wa.gov

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