US Bridges

Ia 37 over Boyer River

Fair

Harrison County, Iowa · 0.1 Mi. W of US 30 · Structure no. 000000000027600

Built
1958
67 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
284 ft
3 main spans
Daily traffic
1,340
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 37 over Boyer River is a steel continuous stringer/multi-beam or girder carrying Ia 37 over Boyer River in Harrison County, Iowa. It was built in 1958, so it is 67 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 1,340 vehicles a day, roughly 12% of them trucks, projected to reach 1,340 by 2043. The structure is 284 ft (86.6 m) long and 34 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesIa 37
CrossesBoyer River
Location0.1 Mi. W of US 30
RouteState Highway 37
CountyHarrison County
StateIowa
Coordinates41.86012, -95.60556
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.1 US tons
Inventory rating25.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length284 ft (86.6 m)
Longest span109 ft (33.2 m)
Deck width34 ft (10.4 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,340 (2022)
Projected traffic1,340 by 2043
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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 37 over Boyer River built?

It was built in 1958, making it 67 years old in 2025.

What condition is Ia 37 over Boyer 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 July 2023.

How much traffic does Ia 37 over Boyer River carry?

About 1,340 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is Ia 37 over Boyer River?

The structure is 284 ft (86.6 m) long with a longest span of 109 ft (33.2 m) and a deck 34 ft wide.

Who owns Ia 37 over Boyer River?

It is owned by the State Highway Agency.