Structure 4562A0000000 · Snohomish County, WA

SR 529 over Union Sl

Carries SR 529 over Union Sl, 5.9 N Jct SR 529 Spur.

Overall conditionPoor

Set by its lowest-rated component: Substructure at 4 of 9.

How ratings work
Deck7/9 · Good
Superstructure7/9 · Good
Substructuresets the rating4/9 · Poor
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT633 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 4/9 · sets the rating

633 ft end to end, longest span 62 ft: about 1.8 football fields. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a tee-beam bridge.

Built195472 years old
Length632.9 ft192.9 m
Daily traffic16,439counted 2023
Last inspectedJuly 2023every 24 months

Location

StateWashington
CountySnohomish
Location5.9 N Jct SR 529 Spur
CarriesSR 529
CrossesUnion Sl
Coordinates48.03047, -122.18297

Physical Characteristics

MaterialConcrete Continuous
DesignTee Beam
Total Length632.9 ft (192.9 m)
Max Span62.0 ft (18.9 m)
Deck Width35.4 ft (10.8 m)
Deck Area2083.3 sq m
Main Spans12
Year Built1954

Traffic

Avg Daily Traffic16,439 (2023)
Truck Traffic6%
Lanes On Bridge2

Inspection & Ownership

Last InspectionJuly 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical4 — Foundations need monitoring
Structure Number0004562A0000000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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