US Bridges

SB US 59 over Boyer River

Fair

Crawford County, Iowa · 0.1 Mi. S of Ia 39 · Structure no. 000000000021500

Built
1967
58 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
291 ft
3 main spans
Daily traffic
4,300
2022 count
Owner
State
State Highway Agency

About this bridge

SB US 59 over Boyer River is a steel continuous stringer/multi-beam or girder carrying SB US 59 over Boyer River in Crawford County, Iowa. It was built in 1967, so it is 58 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 5 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 4,300 vehicles a day, roughly 15% of them trucks, projected to reach 4,300 by 2043. The structure is 291 ft (88.7 m) long and 35 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSB US 59
CrossesBoyer River
Location0.1 Mi. S of Ia 39
RouteU.S. Route 59
CountyCrawford County
StateIowa
Coordinates42.01976, -95.36774
Functional classUrban Other Principal 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 alignment6: Equal to present minimum criteria
Operating rating74.7 US tons
Inventory rating44.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length291 ft (88.7 m)
Longest span112 ft (34.1 m)
Deck width35 ft (10.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,300 (2022)
Projected traffic4,300 by 2043
Trucks15%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 SB US 59 over Boyer River built?

It was built in 1967, making it 58 years old in 2025.

What condition is SB US 59 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 SB US 59 over Boyer River carry?

About 4,300 vehicles per day (2022 count), of which roughly 15% are trucks.

How long is SB US 59 over Boyer River?

The structure is 291 ft (88.7 m) long with a longest span of 112 ft (34.1 m) and a deck 35 ft wide.

Who owns SB US 59 over Boyer River?

It is owned by the State Highway Agency.