US Bridges

SR 6 Ramp to SB I5 over Dillenbaugh CR

Fair

Lewis County, Washington · 6.3 E JCT SR 603 · Structure no. 0010134A0000000

Built
1976
49 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
151 ft
3 main spans
Daily traffic
3,474
2023 count
Owner
State
State Highway Agency

About this bridge

SR 6 Ramp to SB I5 over Dillenbaugh CR is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 6 Ramp to SB I5 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 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 3,474 vehicles a day, roughly 13% of them trucks, projected to reach 4,676 by 2039. The structure is 151 ft (46 m) long and 29 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR 6 Ramp to SB I5
CrossesDillenbaugh CR
Location6.3 E JCT SR 603
RouteState Highway 6
CountyLewis County
StateWashington
Coordinates46.65914, -122.97867
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 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 rating84 US tons
Inventory rating50 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length151 ft (46 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 traffic3,474 (2023)
Projected traffic4,676 by 2039
Trucks13%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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$2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 6 Ramp to SB I5 over Dillenbaugh CR built?

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

What condition is SR 6 Ramp to SB I5 over Dillenbaugh CR 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 2024.

How much traffic does SR 6 Ramp to SB I5 over Dillenbaugh CR carry?

About 3,474 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is SR 6 Ramp to SB I5 over Dillenbaugh CR?

The structure is 151 ft (46 m) long with a longest span of 60 ft (18.3 m) and a deck 29 ft wide.

Who owns SR 6 Ramp to SB I5 over Dillenbaugh CR?

It is owned by the State Highway Agency.