US Bridges

NB I 380 over J Ave NE

Fair

Linn County, Iowa · 2.0 Mi. S of Jct. Ia #100 · Structure no. 000000000604270

Built
1980
45 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
232 ft
4 main spans
Daily traffic
38,800
2022 count
Owner
State
State Highway Agency

About this bridge

NB I 380 over J Ave NE is a prestressed concrete stringer/multi-beam or girder carrying NB I 380 over J Ave NE in Linn County, Iowa. It was built in 1980, so it is 45 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 38,800 vehicles a day, roughly 11% of them trucks, projected to reach 38,800 by 2042. The structure is 232 ft (70.7 m) long and 71 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNB I 380
CrossesJ Ave NE
Location2.0 Mi. S of Jct. Ia #100
RouteInterstate 380
CountyLinn County
StateIowa
Coordinates41.99951, -91.66668
Functional classUrban Principal Arterial - Interstate

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 protection7 GoodSome minor problems.
Last inspectionFebruary 2023
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
Approach roadway alignment7: Better than present minimum criteria
Operating rating72.5 US tons
Inventory rating33.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length232 ft (70.7 m)
Longest span69 ft (21 m)
Deck width71 ft (21.7 m)
Roadway width68 ft (20.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic38,800 (2022)
Projected traffic38,800 by 2042
Trucks11%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 NB I 380 over J Ave NE built?

It was built in 1980, making it 45 years old in 2025.

What condition is NB I 380 over J Ave NE 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 NB I 380 over J Ave NE carry?

About 38,800 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is NB I 380 over J Ave NE?

The structure is 232 ft (70.7 m) long with a longest span of 69 ft (21 m) and a deck 71 ft wide.

Who owns NB I 380 over J Ave NE?

It is owned by the State Highway Agency.