US Bridges

76th Ave SW over I-380

Fair

Linn County, Iowa · 1.5 Mi.S.Of Jct. US 30 · Structure no. 000000000607050

Built
1975
50 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
258 ft
4 main spans
Daily traffic
5,100
2021 count
Owner
State
State Highway Agency

About this bridge

76th Ave SW over I-380 is a prestressed concrete stringer/multi-beam or girder carrying 76th Ave SW over I-380 in Linn County, Iowa. It was built in 1975, so it is 50 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 5,100 vehicles a day, projected to reach 5,100 by 2043. The structure is 258 ft (78.6 m) long and 33 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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Carries76th Ave SW
CrossesI-380
Location1.5 Mi.S.Of Jct. US 30
RouteCity Street 0
CountyLinn County
StateIowa
Coordinates41.90514, -91.67254
Functional classUrban Collector

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.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating75.2 US tons
Inventory rating30.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length258 ft (78.6 m)
Longest span87 ft (26.5 m)
Deck width33 ft (10.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,100 (2021)
Projected traffic5,100 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.9 mi (3 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was 76th Ave SW over I-380 built?

It was built in 1975, making it 50 years old in 2025.

What condition is 76th Ave SW over I-380 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 2023.

How much traffic does 76th Ave SW over I-380 carry?

About 5,100 vehicles per day (2021 count).

How long is 76th Ave SW over I-380?

The structure is 258 ft (78.6 m) long with a longest span of 87 ft (26.5 m) and a deck 33 ft wide.

Who owns 76th Ave SW over I-380?

It is owned by the State Highway Agency.