US Bridges

SR 9 over Snohomish R Overflow

Fair

Snohomish County, Washington · 1.9 N JCT SR 96 · Structure no. 0006347A0000000

Built
1960
65 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete Continuous
Length
371 ft
14 main spans
Daily traffic
29,011
2023 count
Owner
State
State Highway Agency

About this bridge

SR 9 over Snohomish R Overflow is a concrete continuous slab carrying SR 9 over Snohomish R Overflow in Snohomish County, Washington. It was built in 1960, so it is 65 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 371 ft (113.1 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 R Overflow
Location1.9 N JCT SR 96
RouteState Highway 9
CountySnohomish County
StateWashington
Coordinates47.9055, -122.10903
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating31.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans14
Design loadHS 20
Structure length371 ft (113.1 m)
Longest span28 ft (8.5 m)
Deck width34 ft (10.5 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic29,011 (2023)
Projected traffic41,042 by 2039
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
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 statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$8.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 9 over Snohomish R Overflow built?

It was built in 1960, making it 65 years old in 2025.

What condition is SR 9 over Snohomish R Overflow 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 April 2023.

How much traffic does SR 9 over Snohomish R Overflow carry?

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

How long is SR 9 over Snohomish R Overflow?

The structure is 371 ft (113.1 m) long with a longest span of 28 ft (8.5 m) and a deck 34 ft wide.

Who owns SR 9 over Snohomish R Overflow?

It is owned by the State Highway Agency.