US Bridges

US 6 over East Nishnabotna River

Fair

Cass County, Iowa · 2.6 Mi. E of Jct. Ia 48 · Structure no. 000000000017400

Built
1961
64 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
386 ft
3 main spans
Daily traffic
1,760
2022 count
Owner
State
State Highway Agency

About this bridge

US 6 over East Nishnabotna River is a steel continuous stringer/multi-beam or girder carrying US 6 over East Nishnabotna River in Cass County, Iowa. It was built in 1961, so it is 64 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 1,760 vehicles a day, roughly 14% of them trucks, projected to reach 1,760 by 2044. The structure is 386 ft (117.7 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 6
CrossesEast Nishnabotna River
Location2.6 Mi. E of Jct. Ia 48
RouteU.S. Route 6
CountyCass County
StateIowa
Coordinates41.31734, -95.08736
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
Deck7 GoodSome minor problems.
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 protection7 GoodSome minor problems.
Last inspectionMay 2024
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.2 US tons
Inventory rating34.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length386 ft (117.7 m)
Longest span148 ft (45.1 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,760 (2022)
Projected traffic1,760 by 2044
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 US 6 over East Nishnabotna River built?

It was built in 1961, making it 64 years old in 2025.

What condition is US 6 over East Nishnabotna 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 May 2024.

How much traffic does US 6 over East Nishnabotna River carry?

About 1,760 vehicles per day (2022 count), of which roughly 14% are trucks.

How long is US 6 over East Nishnabotna River?

The structure is 386 ft (117.7 m) long with a longest span of 148 ft (45.1 m) and a deck 36 ft wide.

Who owns US 6 over East Nishnabotna River?

It is owned by the State Highway Agency.