Structure 166 · Story County, IA

S 4th ST over Ioway Creek

Carries S 4th ST over Ioway Creek, A14000675.

Overall conditionFair

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

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT230 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 6/9 · sets the rating

230 ft end to end, longest span 80 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.

Built197056 years old
Length230.0 ft70.1 m
Daily traffic11,666counted 2022
Last inspectedApril 2024every 24 months

Location

StateIowa
CountyStory
LocationA14000675
CarriesS 4th ST
CrossesIoway Creek
Coordinates42.01770, -93.62926

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length230.0 ft (70.1 m)
Max Span80.1 ft (24.4 m)
Deck Width58.7 ft (17.9 m)
Deck Area1254.8 sq m
Main Spans3
Year Built1970

Traffic

Avg Daily Traffic11,666 (2022)
Lanes On Bridge4

Inspection & Ownership

Last InspectionApril 2024
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number000000000000166

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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