US Bridges

Main Street over Nooksack River

FairPosted for load

Whatcom County, Washington · At Front ST · Structure no. 085500000000000

Built
1950
75 years old, rebuilt 2004
Condition
Fair
inspected April 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
429 ft
2 main spans
Daily traffic
21,350
2017 count
Owner
City
City or Municipal Highway Agency

About this bridge

Main Street over Nooksack River is a steel continuous girder and floorbeam system carrying Main Street over Nooksack River in Whatcom County, Washington. It was built in 1950 and reconstructed in 2004, so it is 75 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. Its operating status is: posted for load restriction.

It carries about 21,350 vehicles a day, roughly 7% of them trucks, projected to reach 21,400 by 2040. The structure is 429 ft (130.8 m) long and 50 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesMain Street
CrossesNooksack River
LocationAt Front ST
RouteCity Street 445
Coordinates48.845, -122.59
Functional classRural Major Collector

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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 rating38.6 US tons
Inventory rating22.8 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+6 approach)
Design loadHS 15
Structure length429 ft (130.8 m)
Longest span110 ft (33.5 m)
Deck width50 ft (15.1 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,350 (2017)
Projected traffic21,400 by 2040
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$6.9 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Main Street over Nooksack River built?

It was built in 1950, making it 75 years old in 2025. It was reconstructed in 2004.

What condition is Main Street over Nooksack 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 April 2023.

How much traffic does Main Street over Nooksack River carry?

About 21,350 vehicles per day (2017 count), of which roughly 7% are trucks.

How long is Main Street over Nooksack River?

The structure is 429 ft (130.8 m) long with a longest span of 110 ft (33.5 m) and a deck 50 ft wide.

Who owns Main Street over Nooksack River?

It is owned by the City or Municipal Highway Agency.