US Bridges

Ia 70 over Iowa River

Fair

Louisa County, Iowa · 0.9 Mi. N of Jct. Iowa 92 · Structure no. 000000000034061

Built
1989
36 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
581 ft
6 main spans
Daily traffic
2,840
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 70 over Iowa River is a prestressed concrete stringer/multi-beam or girder carrying Ia 70 over Iowa River in Louisa County, Iowa. It was built in 1989, so it is 36 years old, younger 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 2,840 vehicles a day, roughly 8% of them trucks, projected to reach 2,840 by 2044. The structure is 581 ft (177.1 m) long and 44 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

Location

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CarriesIa 70
CrossesIowa River
Location0.9 Mi. N of Jct. Iowa 92
RouteState Highway 70
CountyLouisa County
StateIowa
Coordinates41.29122, -91.36031
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating88.7 US tons
Inventory rating46.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length581 ft (177.1 m)
Longest span97 ft (29.6 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,840 (2022)
Projected traffic2,840 by 2044
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 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 70 over Iowa River built?

It was built in 1989, making it 36 years old in 2025.

What condition is Ia 70 over Iowa 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 April 2024.

How much traffic does Ia 70 over Iowa River carry?

About 2,840 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is Ia 70 over Iowa River?

The structure is 581 ft (177.1 m) long with a longest span of 97 ft (29.6 m) and a deck 44 ft wide.

Who owns Ia 70 over Iowa River?

It is owned by the State Highway Agency.