US Bridges

I-5 over I-5 Drainage

Fair

Skagit County, Washington · 2.6 N JCT 534 · Structure no. 0009392B0000000

Built
1972
53 years old
Condition
Fair
inspected August 2023
Type
Culvert
Steel
Length
75 ft
1 main span
Daily traffic
35,558
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over I-5 Drainage is a steel culvert carrying I-5 over I-5 Drainage in Skagit 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 35,558 vehicles a day, roughly 10% of them trucks, projected to reach 51,975 by 2039. The structure is 75 ft (22.9 m) long.

CarriesI-5
CrossesI-5 Drainage
Location2.6 N JCT 534
RouteInterstate 5
Coordinates48.37868, -122.33508
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating99 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans1 (+2 approach)
Design loadRailroad
Structure length75 ft (22.9 m)
Longest span75 ft (22.9 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35,558 (2023)
Projected traffic51,975 by 2039
Trucks10%
Lanes on structure8
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$4.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-5 over I-5 Drainage built?

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

What condition is I-5 over I-5 Drainage 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 August 2023.

How much traffic does I-5 over I-5 Drainage carry?

About 35,558 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I-5 over I-5 Drainage?

The structure is 75 ft (22.9 m) long with a longest span of 75 ft (22.9 m).

Who owns I-5 over I-5 Drainage?

It is owned by the State Highway Agency.