US Bridges

SB I-29 over BNSF RR & Main ST

Fair

Fremont County, Iowa · 0.4 Mi. N of Mo St. Line · Structure no. 000000000600020

Built
1972
53 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
371 ft
4 main spans
Daily traffic
7,300
2022 count
Owner
State
State Highway Agency

About this bridge

SB I-29 over BNSF RR & Main ST is a steel continuous stringer/multi-beam or girder carrying SB I-29 over BNSF RR & Main ST in Fremont County, Iowa. It was built in 1972, so it is 53 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 7,300 vehicles a day, roughly 39% of them trucks, projected to reach 7,300 by 2042. The structure is 371 ft (113.1 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSB I-29
CrossesBNSF RR & Main ST
Location0.4 Mi. N of Mo St. Line
RouteInterstate 29
CountyFremont County
StateIowa
Coordinates40.58756, -95.65894
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 inspectionJuly 2023
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 alignment8: Equal to present desirable criteria
Operating rating53.7 US tons
Inventory rating32.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length371 ft (113.1 m)
Longest span102 ft (31.1 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,300 (2022)
Projected traffic7,300 by 2042
Trucks39%
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 SB I-29 over BNSF RR & Main ST built?

It was built in 1972, making it 53 years old in 2025.

What condition is SB I-29 over BNSF RR & Main ST 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 July 2023.

How much traffic does SB I-29 over BNSF RR & Main ST carry?

About 7,300 vehicles per day (2022 count), of which roughly 39% are trucks.

How long is SB I-29 over BNSF RR & Main ST?

The structure is 371 ft (113.1 m) long with a longest span of 102 ft (31.1 m) and a deck 43 ft wide.

Who owns SB I-29 over BNSF RR & Main ST?

It is owned by the State Highway Agency.