Structure 28340 · Harrison County, IA

160th ST over I-29

Carries 160th ST over I-29, 1.8 Mi. S Of Jct. SR F20.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructuresets the rating8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT228 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

228 ft end to end, longest span 69 ft: about 3 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.

Built196759 years old
Length228.0 ft69.5 m
Daily traffic34counted 2022
Last inspectedJune 2024every 24 months

Location

StateIowa
CountyHarrison
Location1.8 Mi. S Of Jct. SR F20
Carries160th ST
CrossesI-29
Coordinates41.77690, -96.05084

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length228.0 ft (69.5 m)
Max Span68.9 ft (21 m)
Deck Width28.2 ft (8.6 m)
Deck Area597.7 sq m
Main Spans4
Year Built1967

Traffic

Avg Daily Traffic34 (2022)
Truck Traffic35%
Lanes On Bridge2
Lanes Under Bridge4

Inspection & Ownership

Last InspectionJune 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number000000000028340

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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