US Bridges

County Highway over I-29/COLFAX Separation

Good

Richland County, North Dakota · 9 South of Nd 46 · Structure no. 0029039047

Built
1973
52 years old
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
235 ft
2 main spans
Daily traffic
25
2019 count
Owner
State
State Highway Agency

About this bridge

County Highway over I-29/COLFAX Separation is a steel continuous stringer/multi-beam or girder carrying County Highway over I-29/COLFAX Separation in Richland County, North Dakota. It was built in 1973, so it is 52 years old, older than the North Dakota average of 48.2 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 25 vehicles a day, projected to reach 25 by 2039. The structure is 235 ft (71.6 m) long and 32 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

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CarriesCounty Highway
CrossesI-29/COLFAX Separation
Location9 South of Nd 46
RouteCounty Highway 0
CountyRichland County
StateNorth Dakota
Coordinates46.49991, -96.83153
Functional classRural Local

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating54.1 US tons
Inventory rating32.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length235 ft (71.6 m)
Longest span117 ft (35.7 m)
Deck width32 ft (9.9 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25 (2019)
Projected traffic25 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed14.9 mi (24 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 County Highway over I-29/COLFAX Separation built?

It was built in 1973, making it 52 years old in 2025.

What condition is County Highway over I-29/COLFAX Separation 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 April 2023.

How much traffic does County Highway over I-29/COLFAX Separation carry?

About 25 vehicles per day (2019 count).

How long is County Highway over I-29/COLFAX Separation?

The structure is 235 ft (71.6 m) long with a longest span of 117 ft (35.7 m) and a deck 32 ft wide.

Who owns County Highway over I-29/COLFAX Separation?

It is owned by the State Highway Agency.