Structure 160070 · Fremont County, IA

170 Street over West Nishnabotna River

Carries 170 Street over West Nishnabotna River, 069410801.

Overall conditionPoor

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

How ratings work
Decksets the rating4/9 · Poor
Superstructure5/9 · Fair
Substructure5/9 · Fair
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT344 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 4/9 · sets the ratingSuperstructure 5/9Substructure 5/9

344 ft end to end, longest span 133 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.

Built196066 years old
Length344.2 ft104.9 m
Daily traffic72counted 2021
Last inspectedApril 2023every 24 months

Location

StateIowa
CountyFremont
Location069410801
Carries170 Street
CrossesWest Nishnabotna River
Coordinates40.80121, -95.59049

Physical Characteristics

MaterialSteel Continuous
DesignStringer/Multi-beam
Total Length344.2 ft (104.9 m)
Max Span132.9 ft (40.5 m)
Deck Width22.0 ft (6.7 m)
Deck Area702.8 sq m
Main Spans3
Year Built1960

Traffic

Avg Daily Traffic72 (2021)
Truck Traffic18%
Lanes On Bridge2

Inspection & Ownership

Last InspectionApril 2023
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceHistorical significance is not determined
Scour Critical7 — Countermeasures installed
Structure Number000000000160070

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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