US Bridges

NB SR 539 over Nooksack R Overflow

Good

Whatcom County, Washington · 1.7 N JCT SR 544 · Structure no. 0003802A0000000

Built
1950
75 years old
Condition
Good
inspected May 2024
Type
Slab
Concrete Continuous
Length
438 ft
23 main spans
Daily traffic
7,931
2023 count
Owner
State
State Highway Agency

About this bridge

NB SR 539 over Nooksack R Overflow is a concrete continuous slab carrying NB SR 539 over Nooksack R Overflow in Whatcom County, Washington. It was built in 1950, 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 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 7,931 vehicles a day, roughly 6% of them trucks, projected to reach 12,168 by 2039. The structure is 438 ft (133.5 m) long and 36 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

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CarriesNB SR 539
CrossesNooksack R Overflow
Location1.7 N JCT SR 544
RouteState Highway 539
CountyWhatcom County
StateWashington
Coordinates48.91493, -122.48555
Functional classUrban Other Principal Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
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 rating19.3 US tons
Inventory rating14.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans23
Design loadHS 20
Structure length438 ft (133.5 m)
Longest span22 ft (6.7 m)
Deck width36 ft (11 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,931 (2023)
Projected traffic12,168 by 2039
Trucks6%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed8.7 mi (14 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$8.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was NB SR 539 over Nooksack R Overflow built?

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

What condition is NB SR 539 over Nooksack R Overflow 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 May 2024.

How much traffic does NB SR 539 over Nooksack R Overflow carry?

About 7,931 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is NB SR 539 over Nooksack R Overflow?

The structure is 438 ft (133.5 m) long with a longest span of 22 ft (6.7 m) and a deck 36 ft wide.

Who owns NB SR 539 over Nooksack R Overflow?

It is owned by the State Highway Agency.