US Bridges

SR 524 over Swamp Creek

Fair

Snohomish County, Washington · 1.5 E JCT I-5 · Structure no. 081732000000000

Built
1935
90 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
31 ft
1 main span
Daily traffic
18,981
2023 count
Owner
State
State Highway Agency

About this bridge

SR 524 over Swamp Creek is a wood or timber stringer/multi-beam or girder carrying SR 524 over Swamp Creek in Snohomish County, Washington. It was built in 1935, so it is 90 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 18,981 vehicles a day, roughly 3% of them trucks, projected to reach 27,885 by 2039. The structure is 31 ft (9.4 m) long and 24 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesSR 524
CrossesSwamp Creek
Location1.5 E JCT I-5
RouteState Highway 524
CountySnohomish County
StateWashington
Coordinates47.82509, -122.25547
Functional classUrban Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
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 rating52 US tons
Inventory rating31 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length31 ft (9.4 m)
Longest span29 ft (8.7 m)
Deck width24 ft (7.4 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,981 (2023)
Projected traffic27,885 by 2039
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$398,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 524 over Swamp Creek built?

It was built in 1935, making it 90 years old in 2025.

What condition is SR 524 over Swamp Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in August 2023.

How much traffic does SR 524 over Swamp Creek carry?

About 18,981 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is SR 524 over Swamp Creek?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.7 m) and a deck 24 ft wide.

Who owns SR 524 over Swamp Creek?

It is owned by the State Highway Agency.