Structure 245041 · Mills County, IA

330th ST over Nishnabotna River

Carries 330th ST over Nishnabotna River, 071411502.

Overall conditionGood

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

How ratings work
Decksets the rating7/9 · Good
Superstructure8/9 · Very Good
Substructure8/9 · Very Good
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT389 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9 · sets the ratingSuperstructure 8/9Substructure 8/9

389 ft end to end, longest span 96 ft: about 5 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.

Built201511 years old
Length388.8 ft118.5 m
Daily traffic329counted 2022
Last inspectedApril 2021every 48 months

Location

StateIowa
CountyMills
Location071411502
Carries330th ST
CrossesNishnabotna River
Coordinates40.95761, -95.55639

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length388.8 ft (118.5 m)
Max Span96.5 ft (29.4 m)
Deck Width33.1 ft (10.1 m)
Deck Area1196.8 sq m
Main Spans4
Year Built2015

Traffic

Avg Daily Traffic329 (2022)
Truck Traffic22%
Lanes On Bridge2

Inspection & Ownership

Last InspectionApril 2021
Inspection FrequencyEvery 48 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number000000000245041

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