Structure 17355 161 01541 · Clackamas County, OR

HWY 161 over Molalla River

Carries HWY 161 over Molalla River, 2.7 Mi NE Of Molalla.

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 overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT318 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

318 ft end to end, longest span 159 ft: about 4 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 box-beam bridge.

Built199630 years old
Length317.9 ft96.9 m
Daily traffic6,812counted 2022
Last inspectedJune 2023every 24 months

Location

StateOregon
CountyClackamas
Location2.7 Mi NE Of Molalla
CarriesHWY 161
CrossesMolalla River
Coordinates45.16163, -122.53513

Physical Characteristics

MaterialPrestressed Concrete
DesignBox Beam - Multiple
Total Length317.9 ft (96.9 m)
Max Span159.1 ft (48.5 m)
Deck Width43.3 ft (13.2 m)
Deck Area1279.1 sq m
Main Spans2
Year Built1996

Traffic

Avg Daily Traffic6,812 (2022)
Truck Traffic15%
Lanes On Bridge2

Inspection & Ownership

Last InspectionJune 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number17355 161 01541

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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