US Bridges

Ia 21 over US 30

Good

Benton County, Iowa · Ia 21 U.S. 30 Interchange · Structure no. 000000000700500

Built
2023
2 years old
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
240 ft
2 main spans
Daily traffic
1,860
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 21 over US 30 is a prestressed concrete stringer/multi-beam or girder carrying Ia 21 over US 30 in Benton County, Iowa. It was built in 2023, so it is 2 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 1,860 vehicles a day, roughly 18% of them trucks, projected to reach 1,860 by 2042. The structure is 240 ft (73.2 m) long and 63 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIa 21
CrossesUS 30
LocationIa 21 U.S. 30 Interchange
RouteState Highway 21
CountyBenton County
StateIowa
Coordinates41.96388, -92.29775
Functional classRural Minor Arterial

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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable 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 spans2
Design loadHL 93
Structure length240 ft (73.2 m)
Longest span121 ft (36.9 m)
Deck width63 ft (19.3 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,860 (2022)
Projected traffic1,860 by 2042
Trucks18%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
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 Ia 21 over US 30 built?

It was built in 2023, making it 2 years old in 2025.

What condition is Ia 21 over US 30 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 August 2023.

How much traffic does Ia 21 over US 30 carry?

About 1,860 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is Ia 21 over US 30?

The structure is 240 ft (73.2 m) long with a longest span of 121 ft (36.9 m) and a deck 63 ft wide.

Who owns Ia 21 over US 30?

It is owned by the State Highway Agency.