US Bridges

Marine Drive over Stillaguamish River

Fair

Snohomish County, Washington · 1.4 S SR 532 · Structure no. 084143000000000

Built
1959
66 years old
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
255 ft
5 main spans
Daily traffic
6,596
2022 count
Owner
County
County Highway Agency

About this bridge

Marine Drive over Stillaguamish River is a concrete continuous slab carrying Marine Drive over Stillaguamish River in Snohomish County, Washington. It was built in 1959, so it is 66 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 5 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 6,596 vehicles a day, roughly 12% of them trucks, projected to reach 10,000 by 2046. The structure is 255 ft (77.7 m) long and 36 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesMarine Drive
CrossesStillaguamish River
Location1.4 S SR 532
RouteCounty Highway 96833
CountySnohomish County
StateWashington
Coordinates48.22534, -122.3378
Functional classRural 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46 US tons
Inventory rating27 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length255 ft (77.7 m)
Longest span55 ft (16.8 m)
Deck width36 ft (11.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,596 (2022)
Projected traffic10,000 by 2046
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$9.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Marine Drive over Stillaguamish River built?

It was built in 1959, making it 66 years old in 2025.

What condition is Marine Drive over Stillaguamish River 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 July 2024.

How much traffic does Marine Drive over Stillaguamish River carry?

About 6,596 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is Marine Drive over Stillaguamish River?

The structure is 255 ft (77.7 m) long with a longest span of 55 ft (16.8 m) and a deck 36 ft wide.

Who owns Marine Drive over Stillaguamish River?

It is owned by the County Highway Agency.