US Bridges

30th Ave over I-380

Good

Benton County, Iowa · 1.5 Miles N of JCT Ia 150 · Structure no. 000000000605425

Built
1984
41 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
399 ft
4 main spans
Daily traffic
25
2022 count
Owner
State
State Highway Agency

About this bridge

30th Ave over I-380 is a steel continuous stringer/multi-beam or girder carrying 30th Ave over I-380 in Benton County, Iowa. It was built in 1984, so it is 41 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 25 vehicles a day, projected to reach 25 by 2044. The structure is 399 ft (121.6 m) long and 33 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
Carries30th Ave
CrossesI-380
Location1.5 Miles N of JCT Ia 150
RouteCounty Highway 0
CountyBenton County
StateIowa
Coordinates42.25974, -91.91029
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating62.6 US tons
Inventory rating37.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length399 ft (121.6 m)
Longest span127 ft (38.7 m)
Deck width33 ft (10 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25 (2022)
Projected traffic25 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed6.8 mi (11 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 30th Ave over I-380 built?

It was built in 1984, making it 41 years old in 2025.

What condition is 30th Ave over I-380 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 November 2024.

How much traffic does 30th Ave over I-380 carry?

About 25 vehicles per day (2022 count).

How long is 30th Ave over I-380?

The structure is 399 ft (121.6 m) long with a longest span of 127 ft (38.7 m) and a deck 33 ft wide.

Who owns 30th Ave over I-380?

It is owned by the State Highway Agency.