Structure 32755 · Lemhi County, ID

N. St. Charles over Lemhi River

Carries N. St. Charles over Lemhi River, 0.4 N. 0.3 E. Salmon.

Overall conditionPoor

Set by its lowest-rated component: Substructure at 4 of 9.

How ratings work
Deck7/9 · Good
Superstructure6/9 · Satisfactory
Substructuresets the rating4/9 · Poor
Channelnot part of overall4/9 · Poor
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT79 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 6/9Substructure 4/9 · sets the rating

79 ft end to end, longest span 39 ft. Lengths and the car 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 tee-beam bridge.

Built1948rebuilt 1965
Length79.1 ft24.1 m
Daily traffic310counted 2023
Last inspectedJuly 2024every 12 months

Location

StateIdaho
CountyLemhi
Location0.4 N. 0.3 E. Salmon
CarriesN. St. Charles
CrossesLemhi River
Coordinates45.18158, -113.88889

Physical Characteristics

MaterialPrestressed Concrete
DesignTee Beam
Total Length79.1 ft (24.1 m)
Max Span39.0 ft (11.9 m)
Deck Width16.1 ft (4.9 m)
Deck Area118.1 sq m
Main Spans2
Year Built1948 (reconstructed 1965)

Traffic

Avg Daily Traffic310 (2023)
Truck Traffic5%
Lanes On Bridge1

Inspection & Ownership

Last InspectionJuly 2024
Inspection FrequencyEvery 12 months
OwnerCounty Highway Agency
Historical SignificanceHistorical significance is not determined
Scour Critical4 — Foundations need monitoring
Structure Number000000000032755

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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