US Bridges

NB I-29 over BNSF & Cbec RR

Fair

Pottawattamie County, Iowa · 1.3 Mi. S of Jct. 92 · Structure no. 000000000044580

Built
1968
57 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
233 ft
3 main spans
Daily traffic
12,100
2022 count
Owner
State
State Highway Agency

About this bridge

NB I-29 over BNSF & Cbec RR is a steel continuous stringer/multi-beam or girder carrying NB I-29 over BNSF & Cbec RR in Pottawattamie County, Iowa. It was built in 1968, so it is 57 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 12,100 vehicles a day, roughly 23% of them trucks, projected to reach 12,100 by 2044. The structure is 233 ft (71 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNB I-29
CrossesBNSF & Cbec RR
Location1.3 Mi. S of Jct. 92
RouteInterstate 29
CountyPottawattamie County
StateIowa
Coordinates41.2059, -95.82324
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
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 inspectionMarch 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 geometry7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating49.2 US tons
Inventory rating29.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length233 ft (71 m)
Longest span87 ft (26.5 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,100 (2022)
Projected traffic12,100 by 2044
Trucks23%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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 BNSF & Cbec RR built?

It was built in 1968, making it 57 years old in 2025.

What condition is NB I-29 over BNSF & Cbec 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 March 2024.

How much traffic does NB I-29 over BNSF & Cbec RR carry?

About 12,100 vehicles per day (2022 count), of which roughly 23% are trucks.

How long is NB I-29 over BNSF & Cbec RR?

The structure is 233 ft (71 m) long with a longest span of 87 ft (26.5 m) and a deck 44 ft wide.

Who owns NB I-29 over BNSF & Cbec RR?

It is owned by the State Highway Agency.