Structure P00043037+09021 · Fergus County, MT

US 191 over Box Elder Creek

Carries US 191 over Box Elder Creek, 2m E Roy.

Overall conditionPoor

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

How ratings work
Deck6/9 · Satisfactory
Superstructure6/9 · Satisfactory
Substructuresets the rating4/9 · Poor
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT58 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 4/9 · sets the rating

58 ft end to end, longest span 19 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 multi-beam bridge.

Built1942rebuilt 1962
Length57.7 ft17.6 m
Daily traffic382counted 2023
Last inspectedSeptember 2024every 24 months

Location

StateMontana
CountyFergus
Location2m E Roy
CarriesUS 191
CrossesBox Elder Creek
Coordinates47.33738, -108.90575

Physical Characteristics

MaterialWood or Timber
DesignStringer/Multi-beam
Total Length57.7 ft (17.6 m)
Max Span19.0 ft (5.8 m)
Deck Width38.1 ft (11.6 m)
Deck Area204.2 sq m
Main Spans3
Year Built1942 (reconstructed 1962)

Traffic

Avg Daily Traffic382 (2023)
Truck Traffic6%
Lanes On Bridge2

Inspection & Ownership

Last InspectionSeptember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure NumberP00043037+09021

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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