US Bridges

Slater RD over I-5

Fair

Whatcom County, Washington · 3.9 N JCT SR 539 · Structure no. 0009268B0000000

Built
1972
53 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
320 ft
4 main spans
Daily traffic
11,783
2012 count
Owner
State
State Highway Agency

About this bridge

Slater RD over I-5 is a prestressed concrete continuous stringer/multi-beam or girder carrying Slater RD over I-5 in Whatcom County, Washington. It was built in 1972, so it is 53 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 11,783 vehicles a day, roughly 5% of them trucks, projected to reach 18,287 by 2036. The structure is 320 ft (97.5 m) long and 43 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesSlater RD
CrossesI-5
Location3.9 N JCT SR 539
RouteCounty Highway 0
CountyWhatcom County
StateWashington
Coordinates48.81717, -122.54884
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.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length320 ft (97.5 m)
Longest span103 ft (31.4 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,783 (2012)
Projected traffic18,287 by 2036
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$6.4 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Slater RD over I-5 built?

It was built in 1972, making it 53 years old in 2025.

What condition is Slater RD over I-5 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 I-5 carry?

About 11,783 vehicles per day (2012 count), of which roughly 5% are trucks.

How long is Slater RD over I-5?

The structure is 320 ft (97.5 m) long with a longest span of 103 ft (31.4 m) and a deck 43 ft wide.

Who owns Slater RD over I-5?

It is owned by the State Highway Agency.