US Bridges

Ia 175 over Maple River

Fair

Monona County, Iowa · 3.8 Mi. E of SR L20 · Structure no. 000000000037031

Built
1972
53 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
236 ft
3 main spans
Daily traffic
1,220
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 175 over Maple River is a prestressed concrete stringer/multi-beam or girder carrying Ia 175 over Maple River in Monona County, Iowa. It was built in 1972, so it is 53 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 1,220 vehicles a day, roughly 18% of them trucks, projected to reach 1,220 by 2042. The structure is 236 ft (71.9 m) long and 47 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesIa 175
CrossesMaple River
Location3.8 Mi. E of SR L20
RouteState Highway 175
CountyMonona County
StateIowa
Coordinates42.11556, -95.86255
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating72.4 US tons
Inventory rating41.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length236 ft (71.9 m)
Longest span97 ft (29.6 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,220 (2022)
Projected traffic1,220 by 2042
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ia 175 over Maple River built?

It was built in 1972, making it 53 years old in 2025.

What condition is Ia 175 over Maple River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in June 2023.

How much traffic does Ia 175 over Maple River carry?

About 1,220 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is Ia 175 over Maple River?

The structure is 236 ft (71.9 m) long with a longest span of 97 ft (29.6 m) and a deck 47 ft wide.

Who owns Ia 175 over Maple River?

It is owned by the State Highway Agency.