US Bridges

I 380 NB over US 6

Good

Johnson County, Iowa · I-80 / I-380 Interchange · Structure no. 000000000600411

Built
2021
4 years old
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
287 ft
3 main spans
Daily traffic
26,550
2022 count
Owner
State
State Highway Agency

About this bridge

I 380 NB over US 6 is a prestressed concrete stringer/multi-beam or girder carrying I 380 NB over US 6 in Johnson County, Iowa. It was built in 2021, so it is 4 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 26,550 vehicles a day, roughly 19% of them trucks, projected to reach 26,550 by 2042. The structure is 287 ft (87.5 m) long and 85 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 380 NB
CrossesUS 6
LocationI-80 / I-380 Interchange
RouteInterstate 380
CountyJohnson County
StateIowa
Coordinates41.70509, -91.64194
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length287 ft (87.5 m)
Longest span137 ft (41.8 m)
Deck width85 ft (25.8 m)
Roadway width81 ft (24.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic26,550 (2022)
Projected traffic26,550 by 2042
Trucks19%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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 I 380 NB over US 6 built?

It was built in 2021, making it 4 years old in 2025.

What condition is I 380 NB over US 6 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does I 380 NB over US 6 carry?

About 26,550 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is I 380 NB over US 6?

The structure is 287 ft (87.5 m) long with a longest span of 137 ft (41.8 m) and a deck 85 ft wide.

Who owns I 380 NB over US 6?

It is owned by the State Highway Agency.