US Bridges

SR 9 over Snohomish River

Fair

Snohomish County, Washington · 2.2 N JCT SR 96 · Structure no. 0005727A0000000

Built
1959
66 years old
Condition
Fair
inspected August 2024
Type
Truss - Thru
Steel
Length
1,111 ft
1 main span
Daily traffic
29,011
2023 count
Owner
State
State Highway Agency

About this bridge

SR 9 over Snohomish River is a steel truss - thru carrying SR 9 over Snohomish 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 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 29,011 vehicles a day, roughly 8% of them trucks, projected to reach 41,042 by 2039. The structure is 1,111 ft (338.6 m) long and 34 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSR 9
CrossesSnohomish River
Location2.2 N JCT SR 96
RouteState Highway 9
CountySnohomish County
StateWashington
Coordinates47.90975, -122.10878
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating26 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+10 approach)
Design loadHS 20
Structure length1,111 ft (338.6 m)
Longest span300 ft (91.4 m)
Deck width34 ft (10.4 m)
Roadway width30 ft (9 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic29,011 (2023)
Projected traffic41,042 by 2039
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway, waterway and railroad
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

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$24.3 million (2022 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was SR 9 over Snohomish River built?

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

What condition is SR 9 over Snohomish 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 August 2024.

How much traffic does SR 9 over Snohomish River carry?

About 29,011 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is SR 9 over Snohomish River?

The structure is 1,111 ft (338.6 m) long with a longest span of 300 ft (91.4 m) and a deck 34 ft wide.

Who owns SR 9 over Snohomish River?

It is owned by the State Highway Agency.