US Bridges

US 6 over Iais RR

Fair

Iowa County, Iowa · 1.6 Mi. E of E JCT Ia 21 · Structure no. 000000000029320

Built
1956
69 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
331 ft
4 main spans
Daily traffic
1,000
2022 count
Owner
State
State Highway Agency

About this bridge

US 6 over Iais RR is a steel continuous stringer/multi-beam or girder carrying US 6 over Iais RR in Iowa County, Iowa. It was built in 1956, so it is 69 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 5 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 1,000 vehicles a day, roughly 25% of them trucks, projected to reach 1,000 by 2044. The structure is 331 ft (100.9 m) long and 34 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesUS 6
CrossesIais RR
Location1.6 Mi. E of E JCT Ia 21
RouteU.S. Route 6
CountyIowa County
StateIowa
Coordinates41.74212, -92.24603
Functional classRural Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating42.7 US tons
Inventory rating25.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length331 ft (100.9 m)
Longest span92 ft (28 m)
Deck width34 ft (10.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,000 (2022)
Projected traffic1,000 by 2044
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
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 US 6 over Iais RR built?

It was built in 1956, making it 69 years old in 2025.

What condition is US 6 over Iais RR 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 June 2024.

How much traffic does US 6 over Iais RR carry?

About 1,000 vehicles per day (2022 count), of which roughly 25% are trucks.

How long is US 6 over Iais RR?

The structure is 331 ft (100.9 m) long with a longest span of 92 ft (28 m) and a deck 34 ft wide.

Who owns US 6 over Iais RR?

It is owned by the State Highway Agency.