US Bridges

Interstate 29 over Legal Drain 40

Good

Cass County, North Dakota · 1 South of Harwood · Structure no. 0029072112 L

Built
2010
15 years old
Condition
Good
inspected July 2023
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete Continuous
Length
206 ft
3 main spans
Daily traffic
10,200
2019 count
Owner
State
State Highway Agency

About this bridge

Interstate 29 over Legal Drain 40 is a prestressed concrete continuous box beam or girders - single or spread carrying Interstate 29 over Legal Drain 40 in Cass County, North Dakota. It was built in 2010, so it is 15 years old, younger 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 10,200 vehicles a day, roughly 17% of them trucks, projected to reach 10,200 by 2039. The structure is 206 ft (62.8 m) long and 43 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesInterstate 29
CrossesLegal Drain 40
Location1 South of Harwood
RouteInterstate 29
CountyCass County
StateNorth Dakota
Coordinates46.96951, -96.87601
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.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.3 US tons
Inventory rating30 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length206 ft (62.8 m)
Longest span69 ft (21 m)
Deck width43 ft (13 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,200 (2019)
Projected traffic10,200 by 2039
Trucks17%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$158,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Interstate 29 over Legal Drain 40 built?

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

What condition is Interstate 29 over Legal Drain 40 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 July 2023.

How much traffic does Interstate 29 over Legal Drain 40 carry?

About 10,200 vehicles per day (2019 count), of which roughly 17% are trucks.

How long is Interstate 29 over Legal Drain 40?

The structure is 206 ft (62.8 m) long with a longest span of 69 ft (21 m) and a deck 43 ft wide.

Who owns Interstate 29 over Legal Drain 40?

It is owned by the State Highway Agency.