SR 520 over UNION BAY


+47.64500, -122.29745
47°38'42" N, 122°17'51" W
Source: National Bridge Inventory
Information not verified. Use at your own risk.


Name:SR 520 over UNION BAY
Structure number:0006872A0000000
Location:0.4 E JCT SR 513
Purpose:Carries highway over waterway
Route classification:Principal Arterial - Other Freeways or Expressways (Urban) [12]
Length of largest span:100.1 ft. [30.5 m]
Total length:1902.0 ft. [579.7 m]
Roadway width between curbs:56.1 ft. [17.1 m]
Deck width edge-to-edge:63.0 ft. [19.2 m]
Owner:State Highway Agency [01]
Year built:1963
Historic significance:Bridge is not eligible for the National Register of Historic Places [5]
Design load:MS 18 / HS 20 [5]
Number of main spans:3
Main spans material:Steel [3]
Main spans design:Stringer/Multi-beam or girder [02]
Deck type:Concrete Cast-in-Place [1]
Wearing surface:Monolithic Concrete (concurrently placed with structural deck) [1]

Latest Available Inspection: August 2015 

Good/Fair/Poor Condition:Fair
Status:Open, no restriction [A]
Average daily traffic:40,257 [as of 2012]
Truck traffic:4% of total traffic
Deck condition:Satisfactory [6 out of 9]
Superstructure condition:Satisfactory [6 out of 9]
Substructure condition:Satisfactory [6 out of 9]
Structural appraisal:Equal to present minimum criteria [6]
Deck geometry appraisal:Meets minimum tolerable limits to be left in place as is [4]
Water adequacy appraisal:Equal to present desirable criteria [8]
Roadway alignment appraisal:Equal to present desirable criteria [8]
Channel protection:Banks are protected or well vegetated. River control devices such as spur dikes and embankment protection are not required or are in a stable condition. [8]
Scour condition:Bridge foundations determined to be stable for the assessed or calculated scour condition. [8]
Operating rating:48.5 tons [44.1 metric tons]
Inventory rating:28.7 tons [26.1 metric tons]
Sufficiency rating:81.5

Previous Inspections 

DateSuff. RatingConditionDeckSuperstructureSubstructureSD/FOADT
August 201581.5FairSatisfactorySatisfactorySatisfactory-40257
July 201386.7FairSatisfactorySatisfactorySatisfactory-40257
July 201183.6FairSatisfactorySatisfactorySatisfactory-70593
July 200982.9FairSatisfactorySatisfactoryGood-77871
July 200784.0FairSatisfactorySatisfactoryGood-77302
July 200583.0FairSatisfactorySatisfactoryGood-77302
December 200384.0FairSatisfactorySatisfactoryGood-77302
September 200184.0FairSatisfactorySatisfactoryGood-77302
July 199984.0FairSatisfactorySatisfactoryGood-77302
December 199784.0FairSatisfactorySatisfactoryGood-77302
November 199591.1FairSatisfactorySatisfactoryGood-77302
December 199491.1FairSatisfactoryGoodGood-77302
April 199286.7PoorPoorGoodGoodSD93250