Structure 11430A0000000 · Lewis County, WA

I-5 over Dillenbaugh Creek

Carries I-5 over Dillenbaugh Creek, 6.8 N Jct SR 508.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.

How ratings work
Decksets the rating7/9 · Good
Superstructuresets the rating7/9 · Good
Substructuresets the rating7/9 · Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT162 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

162 ft end to end, longest span 22 ft: about 2 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a slab bridge.

Built1952rebuilt 1979
Length162.1 ft49.4 m
Daily traffic32,739counted 2023
Last inspectedSeptember 2024every 24 months

Location

StateWashington
CountyLewis
Location6.8 N Jct SR 508
CarriesI-5
CrossesDillenbaugh Creek
Coordinates46.65874, -122.97792

Physical Characteristics

MaterialConcrete Continuous
DesignSlab
Total Length162.1 ft (49.4 m)
Max Span22.0 ft (6.7 m)
Deck Width84.0 ft (25.6 m)
Deck Area1264.6 sq m
Main Spans8
Year Built1952 (reconstructed 1979)

Traffic

Avg Daily Traffic32,739 (2023)
Truck Traffic21%
Lanes On Bridge4

Inspection & Ownership

Last InspectionSeptember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number0011430A0000000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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