Structure 236221 · Mahaska County, IA

FM over South Skunk River

Carries FM over South Skunk River, 075141504.

Overall conditionFair

Set by its lowest-rated component: Deck at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructure7/9 · Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT453 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

453 ft end to end, longest span 97 ft: about 6 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 multi-beam bridge.

Built198244 years old
Length453.1 ft138.1 m
Daily traffic330counted 2022
Last inspectedDecember 2024every 48 months

Location

StateIowa
CountyMahaska
Location075141504
CarriesFM
CrossesSouth Skunk River
Coordinates41.29860, -92.46741

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length453.1 ft (138.1 m)
Max Span97.1 ft (29.6 m)
Deck Width33.1 ft (10.1 m)
Deck Area1394.8 sq m
Main Spans5
Year Built1982

Traffic

Avg Daily Traffic330 (2022)
Truck Traffic17%
Lanes On Bridge2

Inspection & Ownership

Last InspectionDecember 2024
Inspection FrequencyEvery 48 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number000000000236221

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.

Nearby Bridges