US Bridges

I-5 N-W Ramp over Dillenbaugh CR

Good

Lewis County, Washington · 6.8 N JCT SR 508 · Structure no. 0010134B0000000

Built
1976
49 years old
Condition
Good
inspected August 2021
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
136 ft
3 main spans
Daily traffic
3,324
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 N-W Ramp over Dillenbaugh CR is a prestressed concrete continuous stringer/multi-beam or girder carrying I-5 N-W Ramp over Dillenbaugh CR in Lewis County, Washington. It was built in 1976, so it is 49 years old, younger 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 3,324 vehicles a day, roughly 13% of them trucks, projected to reach 4,577 by 2039. The structure is 136 ft (41.5 m) long and 29 ft wide.

Location

Open in Google Maps
CarriesI-5 N-W Ramp
CrossesDillenbaugh CR
Location6.8 N JCT SR 508
RouteInterstate 5
CountyLewis County
StateWashington
Coordinates46.6588, -122.97761
Functional classUrban Principal Arterial - Interstate

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 protection7 GoodSome minor problems.
Last inspectionAugust 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.9 US tons
Inventory rating53 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length136 ft (41.5 m)
Longest span60 ft (18.3 m)
Deck width29 ft (8.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,324 (2023)
Projected traffic4,577 by 2039
Trucks13%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
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$1.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-5 N-W Ramp over Dillenbaugh CR built?

It was built in 1976, making it 49 years old in 2025.

What condition is I-5 N-W Ramp over Dillenbaugh CR 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 August 2021.

How much traffic does I-5 N-W Ramp over Dillenbaugh CR carry?

About 3,324 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is I-5 N-W Ramp over Dillenbaugh CR?

The structure is 136 ft (41.5 m) long with a longest span of 60 ft (18.3 m) and a deck 29 ft wide.

Who owns I-5 N-W Ramp over Dillenbaugh CR?

It is owned by the State Highway Agency.