US Bridges

84 TH Ave W over Chase Lake

Fair

Snohomish County, Washington · 0.6 SW JCT SR 99 · Structure no. 084063000000000

Built
1968
57 years old
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
454 ft
16 main spans
Daily traffic
4,386
2021 count
Owner
County
County Highway Agency

About this bridge

84 TH Ave W over Chase Lake is a concrete continuous slab carrying 84 TH Ave W over Chase Lake in Snohomish County, Washington. It was built in 1968, so it is 57 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 4,386 vehicles a day, roughly 5% of them trucks, projected to reach 7,500 by 2046. The structure is 454 ft (138.4 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries84 TH Ave W
CrossesChase Lake
Location0.6 SW JCT SR 99
RouteCounty Highway 90505
CountySnohomish County
StateWashington
Coordinates47.79699, -122.34644
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating24 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans16
Design loadHS 20
Structure length454 ft (138.4 m)
Longest span29 ft (8.8 m)
Deck width42 ft (12.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,386 (2021)
Projected traffic7,500 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$16.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 84 TH Ave W over Chase Lake built?

It was built in 1968, making it 57 years old in 2025.

What condition is 84 TH Ave W over Chase Lake 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 84 TH Ave W over Chase Lake carry?

About 4,386 vehicles per day (2021 count), of which roughly 5% are trucks.

How long is 84 TH Ave W over Chase Lake?

The structure is 454 ft (138.4 m) long with a longest span of 29 ft (8.8 m) and a deck 42 ft wide.

Who owns 84 TH Ave W over Chase Lake?

It is owned by the County Highway Agency.