US Bridges

SR 529 over Snohomish River

PoorPosted for load

Snohomish County, Washington · 4.6 N JCT SR 529 Spur · Structure no. 0000965A0000000

Built
1927
98 years old, rebuilt 1994
Condition
Poor
inspected July 2022
Type
Movable - Lift
Steel
Length
2,680 ft
1 main span
Daily traffic
16,286
2023 count
Owner
State
State Highway Agency

About this bridge

SR 529 over Snohomish River is a steel movable - lift carrying SR 529 over Snohomish River in Snohomish County, Washington. It was built in 1927 and reconstructed in 1994, so it is 98 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 16,286 vehicles a day, roughly 6% of them trucks, projected to reach 24,967 by 2039. The structure is 2,680 ft (816.9 m) long and 25 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR 529
CrossesSnohomish River
Location4.6 N JCT SR 529 Spur
RouteState Highway 529
CountySnohomish County
StateWashington
Coordinates48.01215, -122.18942
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2022
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30 US tons
Inventory rating18 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+30 approach)
Design loadH 20
Structure length2,680 ft (816.9 m)
Longest span180 ft (54.9 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic16,286 (2023)
Projected traffic24,967 by 2039
Trucks6%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesHighway, waterway and railroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$40.7 million (2022 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was SR 529 over Snohomish River built?

It was built in 1927, making it 98 years old in 2025. It was reconstructed in 1994.

What condition is SR 529 over Snohomish River in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2022.

How much traffic does SR 529 over Snohomish River carry?

About 16,286 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 529 over Snohomish River?

The structure is 2,680 ft (816.9 m) long with a longest span of 180 ft (54.9 m) and a deck 25 ft wide.

Who owns SR 529 over Snohomish River?

It is owned by the State Highway Agency.