SR 520 over UNION BAY


+47.64477, -122.29868
47°38'41" N, 122°17'55" 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 2017

Good/Fair/Poor Condition:Fair
Status:Open, no restriction [A]
Average daily traffic:47,290 [as of 2016]
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]
Sufficiency rating:80.9
Recommended work:Bridge rehabilitation because of general structure deterioration or inadequate strength. [35]
Estimated cost of work:$47,170,000

Previous Inspections

DateConditionDeckSuperstructureSubstructureADTSuff. Rating
August 2017FairSatisfactorySatisfactorySatisfactory4729080.9
August 2015FairSatisfactorySatisfactorySatisfactory4025781.5
July 2013FairSatisfactorySatisfactorySatisfactory4025786.7
July 2011FairSatisfactorySatisfactorySatisfactory7059383.6
July 2009FairSatisfactorySatisfactoryGood7787182.9
July 2007FairSatisfactorySatisfactoryGood7730284.0
July 2005FairSatisfactorySatisfactoryGood7730283.0
December 2003FairSatisfactorySatisfactoryGood7730284.0
September 2001FairSatisfactorySatisfactoryGood7730284.0
July 1999FairSatisfactorySatisfactoryGood7730284.0
December 1997FairSatisfactorySatisfactoryGood7730284.0
November 1995FairSatisfactorySatisfactoryGood7730291.1
December 1994FairSatisfactoryGoodGood7730291.1
April 1992PoorPoorGoodGood9325086.7

Element Data

Source: National Bridge Elements dataset, 2019 edition. This feature is experimental.
Steel Girder/Beamlinear ft.2,9002,900000
Steel Protective Coatingsq. ft.27,50013,475013,750275
Prestressed Concrete Girder/Beamlinear ft.19,43419,429050
Reinforced Concrete Decksq. ft.134,471134,4125009
Reinforced Concrete Top Flangesq. ft.1,8881,64824000
Reinforced Concrete Pier Walllinear ft.7674020
Reinforced Concrete Abutmentlinear ft.133133000
Reinforced Concrete Pile Cap/Footinglinear ft.11000
Prestressed Concrete Pileeach8585000
Reinforced Concrete Pier Caplinear ft.1,3441,344000
Strip Seal Jointlinear ft.140000140
Compression Jointlinear ft.1,20400651553
Assembly without Seal Jointlinear ft.2100021
Elastomeric Bearingeach390385050
Movable Bearingeach2929000
Fixed Bearingeach2929000
Bridge Rail
Steel or Aluminum Bridge Raillinear ft.2,8532,8054800
Reinforced Concrete Bridge Raillinear ft.5,7065,698080
Reinforced Concrete Slabsq. ft.1,8881,888000