•  2003 Project Highlights
•  Evaluation Criteria

SR 520 - 10th to Midspan Evergreen Point Bridge

King County

Design: Construction Management: Schedule: Cost: Engineers Estimate: $3,679,661 Contract Award Amount: $3,186,476 Estimated cost for completion: $3,362,207 For the most part there was good teamwork between WSDOT and Colvico, Inc. Open communication throughout the project led to its successful and safe completion. There were, however, innovations and significant challenges in using a new product and coordinating with a third party.

This electrical rehabilitation project was in the vicinity of State Route 520 from the 10th Street undercrossing to the Evergreen Point Floating Bridge mid-span. Crews increased lighting, upgraded aging electrical transformers inside the bridge and installed new transformers. They also installed three new traffic cameras, two at Montlake Boulevard and one at the Lake Washington Boulevard overcrossing, and replaced one, at the Lake Washington Boulevard off-ramp from westbound SR 520. In addition, crews installed Whelen Trackers, which count vehicles using the highway. The new streetlights enhance safety by increasing visibility on the bridge. The cameras and Whelen Trackers help drivers, reporters and WSDOT staff get better real-time traffic information.

Construction Summary

This project was completed nearly within budget and 58 days later than planned. Work was halted for three months to avoid shutting down the main power system in the winter, when there's a risk of high winds. High wind in one direction creates high waves that slam against one side of the floating bridge. The draw span of the bridge must be opened occasionally to relieve the water pressure against the bridge and protect the steel cables that anchor the bridge. Electricity is required to open the draw span.

Whelen Trackers were installed for the first time on a WSDOT project. Whelen Trackers use microwave radar detector, similar to those used for police radar, to count vehicles and measure their speed. This data is then compiled and transmitted to WSDOT's central computer in Shoreline. Four steel boxes containing the devices were mounted to the rail of the maintenance walkway over the bridge. Whelen Trackers allow us to gather traffic data without installing loops under the pavement. Intensive coordination among WSDOT's Intelligent Transportation System Office, the contractor, and suppliers was required.

In addition, coordination with Seattle City Light was very challenging. The project contract required the city to install a new 26-kilovolt cable and high voltage transformer near the Seattle Museum of History and Industry. We were not able to complete this step in a timely manner due to Seattle City Light mid-project revisions to electrical voltage requirements and personnel changes.

Fliers were distributed to everyone who lives within 500 feet of construction areas to let them know about upcoming construction activities and the project schedule and contacts.

Contractor:
Colvico, Inc.

WSDOT Contact:
Messay Shiferaw
Phone: 253-768-5862
E-mail: shifme@wsdot.wa.gov

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