US Bridges

Mountain Loop HWY over Benson Creek

Good

Snohomish County, Washington · 11.2 MI E JCT SR 92 · Structure no. 086155000000000

Built
1995
30 years old
Condition
Good
inspected June 2023
Type
Slab
Prestressed Concrete
Length
67 ft
1 main span
Daily traffic
3,520
2022 count
Owner
County
County Highway Agency

About this bridge

Mountain Loop HWY over Benson Creek is a prestressed concrete slab carrying Mountain Loop HWY over Benson Creek in Snohomish County, Washington. It was built in 1995, so it is 30 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,520 vehicles a day, roughly 5% of them trucks, projected to reach 4,000 by 2045. The structure is 67 ft (20.4 m) long and 36 ft wide. If it were closed, the detour would be 93.8 mi (151 km).

Location

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CarriesMountain Loop HWY
CrossesBenson Creek
Location11.2 MI E JCT SR 92
RouteCounty Highway 98960
CountySnohomish County
StateWashington
Coordinates48.09066, -121.77844
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating69 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 25 or greater
Structure length67 ft (20.4 m)
Longest span64 ft (19.5 m)
Deck width36 ft (11 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,520 (2022)
Projected traffic4,000 by 2045
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed93.8 mi (151 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$2.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mountain Loop HWY over Benson Creek built?

It was built in 1995, making it 30 years old in 2025.

What condition is Mountain Loop HWY over Benson Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in June 2023.

How much traffic does Mountain Loop HWY over Benson Creek carry?

About 3,520 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is Mountain Loop HWY over Benson Creek?

The structure is 67 ft (20.4 m) long with a longest span of 64 ft (19.5 m) and a deck 36 ft wide.

Who owns Mountain Loop HWY over Benson Creek?

It is owned by the County Highway Agency.