US Bridges

27th Ave over I-380

Fair

Linn County, Iowa · 1.7 Mi. N of Jct. US 30 · Structure no. 000000000607030

Built
1975
50 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
258 ft
4 main spans
Daily traffic
939
2022 count
Owner
State
State Highway Agency

About this bridge

27th Ave over I-380 is a prestressed concrete stringer/multi-beam or girder carrying 27th Ave 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 939 vehicles a day, projected to reach 939 by 2043. The structure is 258 ft (78.6 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries27th Ave
CrossesI-380
Location1.7 Mi. N of Jct. US 30
RouteCity Street 0
CountyLinn County
StateIowa
Coordinates41.95142, -91.67138
Functional classUrban Local

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 inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating99.8 US tons
Inventory rating39.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length258 ft (78.6 m)
Longest span91 ft (27.7 m)
Deck width41 ft (12.5 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic939 (2022)
Projected traffic939 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was 27th Ave over I-380 built?

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

What condition is 27th Ave 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 February 2023.

How much traffic does 27th Ave over I-380 carry?

About 939 vehicles per day (2022 count).

How long is 27th Ave over I-380?

The structure is 258 ft (78.6 m) long with a longest span of 91 ft (27.7 m) and a deck 41 ft wide.

Who owns 27th Ave over I-380?

It is owned by the State Highway Agency.