Local bridges also are cause for concern

On a scale of 0 to 100, the small King County Bridge that crosses the Green River between Kent and the King County border is a 2.

That means it is in the worst condition of bridges maintained by the county.

But there is no money to replace the Alvord T Bridge, even though it is narrow with overhead restrictions and structural problems, said Tim Lane, supervising engineer with the King County bridge group. Built in 1914 and rebuilt in 1970, the truss bridge also has load restrictions.

Those problems are what placed it as a 2 on a federal scale used to measure bridges. The ratings are based on a bridge's structural soundness and ability to handle traffic.

Both the county and the city of Seattle typically inspect bridges every two years, more often if there are concerns. The county is responsible for 179 bridges and the city for 149.

Several bridges in Seattle have structural problems, said Richard Miller, director of roadway structures:

• The Magnolia Bridge. The city wants to replace the bridge, which was damaged in the 2001 Nisqually earthquake, but there is no money.

• The 45th Street Viaduct. The timbers are rotting and the city plans to replace the section of the viaduct from the Burke-Gilman Trail to the west end of the structure, using some of the $128 million approved by voters last November in the city's Bridging the Gap levy.

• The bridge at 15th Avenue Northeast and Northeast 105th Street. The city is monitoring cracks on the bridge. "We're concerned about structural capacity," Miller said, adding that Metro buses must slow to 20 miles per hour when crossing it.

• The Jose Rizal Bridge in South Seattle. Concrete is coming loose on the deck's underside and the city hopes to do repairs. It is being repainted to prevent corrosion.

Miller said the average age of Seattle's bridges is 55 years.

"We feel the bridges are safe," he said, "but our bridge inventory is getting older and trucks are getting heavier, which presents problems for us."

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com