US Bridges

170th ST over Coulee

PoorPosted for load

Fayette County, Iowa · 093091301 · Structure no. 000000000151420

Built
1915
110 years old
Condition
Poor
inspected October 2024
Type
Arch - Deck
Concrete
Length
35 ft
1 main span
Daily traffic
44
2022 count
Owner
County
County Highway Agency

About this bridge

170th ST over Coulee is a concrete arch - deck carrying 170th ST over Coulee in Fayette County, Iowa. It was built in 1915, so it is 110 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 44 vehicles a day, projected to reach 44 by 2044. The structure is 35 ft (10.7 m) long and 20 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
Carries170th ST
CrossesCoulee
Location093091301
RouteCounty Highway 0
CountyFayette County
StateIowa
Coordinates42.87591, -91.85526
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating17.7 US tons
Inventory rating13.2 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length35 ft (10.7 m)
Longest span35 ft (10.7 m)
Deck width20 ft (6.2 m)
Roadway width18 ft (5.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic44 (2022)
Projected traffic44 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost$130,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 170th ST over Coulee built?

It was built in 1915, making it 110 years old in 2025.

What condition is 170th ST over Coulee in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in October 2024.

How much traffic does 170th ST over Coulee carry?

About 44 vehicles per day (2022 count).

How long is 170th ST over Coulee?

The structure is 35 ft (10.7 m) long with a longest span of 35 ft (10.7 m) and a deck 20 ft wide.

Who owns 170th ST over Coulee?

It is owned by the County Highway Agency.