US Bridges

NB I-29 over UP RR & K-45

Fair

Harrison County, Iowa · 1.9 Mi. N of SR F-50 · Structure no. 000000000028190

Built
1967
58 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
455 ft
4 main spans
Daily traffic
7,600
2022 count
Owner
State
State Highway Agency

About this bridge

NB I-29 over UP RR & K-45 is a steel continuous stringer/multi-beam or girder carrying NB I-29 over UP RR & K-45 in Harrison County, Iowa. It was built in 1967, so it is 58 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 7,600 vehicles a day, roughly 31% of them trucks, projected to reach 7,600 by 2044. The structure is 455 ft (138.7 m) long and 33 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNB I-29
CrossesUP RR & K-45
Location1.9 Mi. N of SR F-50
RouteInterstate 29
CountyHarrison County
StateIowa
Coordinates41.6397, -96.01278
Functional classRural 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating64.2 US tons
Inventory rating38.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length455 ft (138.7 m)
Longest span125 ft (38.1 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,600 (2022)
Projected traffic7,600 by 2044
Trucks31%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 NB I-29 over UP RR & K-45 built?

It was built in 1967, making it 58 years old in 2025.

What condition is NB I-29 over UP RR & K-45 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 May 2024.

How much traffic does NB I-29 over UP RR & K-45 carry?

About 7,600 vehicles per day (2022 count), of which roughly 31% are trucks.

How long is NB I-29 over UP RR & K-45?

The structure is 455 ft (138.7 m) long with a longest span of 125 ft (38.1 m) and a deck 33 ft wide.

Who owns NB I-29 over UP RR & K-45?

It is owned by the State Highway Agency.