US Bridges

County Hiway 3912 over I-29/COLFAX Interchange

Good

Richland County, North Dakota · 11 South of Nd 46 · Structure no. 0029037043

Built
1973
52 years old, rebuilt 2003
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
235 ft
2 main spans
Daily traffic
530
2019 count
Owner
State
State Highway Agency

About this bridge

County Hiway 3912 over I-29/COLFAX Interchange is a steel continuous stringer/multi-beam or girder carrying County Hiway 3912 over I-29/COLFAX Interchange in Richland County, North Dakota. It was built in 1973 and reconstructed in 2003, 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 530 vehicles a day, roughly 14% of them trucks, projected to reach 530 by 2039. The structure is 235 ft (71.6 m) long and 38 ft wide.

Location

Open in Google Maps
CarriesCounty Hiway 3912
CrossesI-29/COLFAX Interchange
Location11 South of Nd 46
RouteCounty Highway 3912
CountyRichland County
StateNorth Dakota
Coordinates46.47092, -96.83082
Functional classRural Major Collector

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 rating54.9 US tons
Inventory rating32.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadH 20
Structure length235 ft (71.6 m)
Longest span117 ft (35.7 m)
Deck width38 ft (11.7 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic530 (2019)
Projected traffic530 by 2039
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
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 Hiway 3912 over I-29/COLFAX Interchange built?

It was built in 1973, making it 52 years old in 2025. It was reconstructed in 2003.

What condition is County Hiway 3912 over I-29/COLFAX Interchange 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 Hiway 3912 over I-29/COLFAX Interchange carry?

About 530 vehicles per day (2019 count), of which roughly 14% are trucks.

How long is County Hiway 3912 over I-29/COLFAX Interchange?

The structure is 235 ft (71.6 m) long with a longest span of 117 ft (35.7 m) and a deck 38 ft wide.

Who owns County Hiway 3912 over I-29/COLFAX Interchange?

It is owned by the State Highway Agency.