US Bridges

NB I-29 over Waubonsie Ditch

Good

Fremont County, Iowa · 0.5 Mi. S of Jct. SR L31 · Structure no. 000000000025591

Built
2010
15 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
247 ft
3 main spans
Daily traffic
6,450
2022 count
Owner
State
State Highway Agency

About this bridge

NB I-29 over Waubonsie Ditch is a prestressed concrete stringer/multi-beam or girder carrying NB I-29 over Waubonsie Ditch in Fremont County, Iowa. It was built in 2010, so it is 15 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 6,450 vehicles a day, roughly 32% of them trucks, projected to reach 6,450 by 2044. The structure is 247 ft (75.3 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesNB I-29
CrossesWaubonsie Ditch
Location0.5 Mi. S of Jct. SR L31
RouteInterstate 29
CountyFremont County
StateIowa
Coordinates40.87959, -95.80067
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: 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 spans3
Design loadHL 93
Structure length247 ft (75.3 m)
Longest span97 ft (29.6 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,450 (2022)
Projected traffic6,450 by 2044
Trucks32%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was NB I-29 over Waubonsie Ditch built?

It was built in 2010, making it 15 years old in 2025.

What condition is NB I-29 over Waubonsie Ditch 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 October 2024.

How much traffic does NB I-29 over Waubonsie Ditch carry?

About 6,450 vehicles per day (2022 count), of which roughly 32% are trucks.

How long is NB I-29 over Waubonsie Ditch?

The structure is 247 ft (75.3 m) long with a longest span of 97 ft (29.6 m) and a deck 43 ft wide.

Who owns NB I-29 over Waubonsie Ditch?

It is owned by the State Highway Agency.