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 

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. ratingEvaluationDeckSuper.Sub.ADT
August 201581.5Not deficientSatisfactorySatisfactorySatisfactory40257
July 201386.7Not deficientSatisfactorySatisfactorySatisfactory40257
July 201183.6Not deficientSatisfactorySatisfactorySatisfactory70593
July 200982.9Not deficientSatisfactorySatisfactoryGood77871
July 200784.0Not deficientSatisfactorySatisfactoryGood77302
July 200583.0Not deficientSatisfactorySatisfactoryGood77302
December 200384.0Not deficientSatisfactorySatisfactoryGood77302
September 200184.0Not deficientSatisfactorySatisfactoryGood77302
July 199984.0Not deficientSatisfactorySatisfactoryGood77302
December 199784.0Not deficientSatisfactorySatisfactoryGood77302
November 199591.1Not deficientSatisfactorySatisfactoryGood77302
December 199491.1Not deficientSatisfactoryGoodGood77302
April 199286.7Structurally deficientPoorGoodGood93250