US Bridges

US 30 over Allen Creek

Fair

Harrison County, Iowa · 0.9 Mi. W of JCT.29 · Structure no. 000000000027370

Built
1929
96 years old, rebuilt 1966
Condition
Fair
inspected April 2024
Type
Slab
Concrete Continuous
Length
73 ft
3 main spans
Daily traffic
6,500
2022 count
Owner
State
State Highway Agency

About this bridge

US 30 over Allen Creek is a concrete continuous slab carrying US 30 over Allen Creek in Harrison County, Iowa. It was built in 1929 and reconstructed in 1966, so it is 96 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 6,500 vehicles a day, roughly 19% of them trucks, projected to reach 6,500 by 2044. The structure is 73 ft (22.3 m) long and 35 ft wide. If it were closed, the detour would be 23 mi (37 km).

Location

Open in Google Maps
CarriesUS 30
CrossesAllen Creek
Location0.9 Mi. W of JCT.29
RouteU.S. Route 30
CountyHarrison County
StateIowa
Coordinates41.55003, -95.92914
Functional classRural Principal Arterial - Other

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.5 US tons
Inventory rating25.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length73 ft (22.3 m)
Longest span27 ft (8.2 m)
Deck width35 ft (10.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,500 (2022)
Projected traffic6,500 by 2044
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed23 mi (37 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 30 over Allen Creek built?

It was built in 1929, making it 96 years old in 2025. It was reconstructed in 1966.

What condition is US 30 over Allen Creek 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 April 2024.

How much traffic does US 30 over Allen Creek carry?

About 6,500 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is US 30 over Allen Creek?

The structure is 73 ft (22.3 m) long with a longest span of 27 ft (8.2 m) and a deck 35 ft wide.

Who owns US 30 over Allen Creek?

It is owned by the State Highway Agency.