US Bridges

I 380 NB Off Ramp over 8th Ave SW

Fair

Linn County, Iowa · 0.5 Mi. S Jct. Ia 922 · Structure no. 000000000605990

Built
1975
50 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
246 ft
5 main spans
Daily traffic
8,500
2022 count
Owner
State
State Highway Agency

About this bridge

I 380 NB Off Ramp over 8th Ave SW is a steel continuous stringer/multi-beam or girder carrying I 380 NB Off Ramp over 8th Ave SW 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 8,500 vehicles a day, roughly 3% of them trucks, projected to reach 8,500 by 2044. The structure is 246 ft (75 m) long and 23 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 380 NB Off Ramp
Crosses8th Ave SW
Location0.5 Mi. S Jct. Ia 922
RouteInterstate 380
CountyLinn County
StateIowa
Coordinates41.96851, -91.67146
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating74.2 US tons
Inventory rating44.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length246 ft (75 m)
Longest span72 ft (21.9 m)
Deck width23 ft (7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,500 (2022)
Projected traffic8,500 by 2044
Trucks3%
Lanes on structure1
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 Off Ramp over 8th Ave SW built?

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

What condition is I 380 NB Off Ramp over 8th Ave SW 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 September 2024.

How much traffic does I 380 NB Off Ramp over 8th Ave SW carry?

About 8,500 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is I 380 NB Off Ramp over 8th Ave SW?

The structure is 246 ft (75 m) long with a longest span of 72 ft (21.9 m) and a deck 23 ft wide.

Who owns I 380 NB Off Ramp over 8th Ave SW?

It is owned by the State Highway Agency.