US Bridges

Slater RD over Nooksack River

Fair

Whatcom County, Washington · 02.43 W of NW DR · Structure no. 080310000000000

Built
1957
68 years old
Condition
Fair
inspected April 2023
Type
Truss - Thru
Steel
Length
246 ft
1 main span
Daily traffic
12,802
2019 count
Owner
County
County Highway Agency

About this bridge

Slater RD over Nooksack River is a steel truss - thru carrying Slater RD over Nooksack River in Whatcom County, Washington. It was built in 1957, so it is 68 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 12,802 vehicles a day, roughly 7% of them trucks, projected to reach 15,000 by 2041. The structure is 246 ft (75 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesSlater RD
CrossesNooksack River
Location02.43 W of NW DR
RouteCounty Highway 14760
CountyWhatcom County
StateWashington
Coordinates48.81903, -122.58056
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
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 rating61.9 US tons
Inventory rating37 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length246 ft (75 m)
Longest span240 ft (73.2 m)
Deck width32 ft (9.9 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck15 ft (4.7 m)

Traffic and service

Average daily traffic12,802 (2019)
Projected traffic15,000 by 2041
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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$9.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Slater RD over Nooksack River built?

It was built in 1957, making it 68 years old in 2025.

What condition is Slater RD 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 Slater RD over Nooksack River carry?

About 12,802 vehicles per day (2019 count), of which roughly 7% are trucks.

How long is Slater RD over Nooksack River?

The structure is 246 ft (75 m) long with a longest span of 240 ft (73.2 m) and a deck 32 ft wide.

Who owns Slater RD over Nooksack River?

It is owned by the County Highway Agency.