US Bridges

US-31 SB over Hart-Montague Trail

Fair

Oceana County, Michigan · 2.5 MI S of Rothbury · Structure no. 000000000008325

Built
1974
51 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
177 ft
3 main spans
Daily traffic
6,360
2007 count
Owner
State
State Highway Agency

About this bridge

US-31 SB over Hart-Montague Trail is a steel stringer/multi-beam or girder carrying US-31 SB over Hart-Montague Trail in Oceana County, Michigan. It was built in 1974, so it is 51 years old, older than the Michigan average of 48.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 6,360 vehicles a day, roughly 9% of them trucks, projected to reach 7,766 by 2018. The structure is 177 ft (53.9 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS-31 SB
CrossesHart-Montague Trail
Location2.5 MI S of Rothbury
RouteU.S. Route 31
CountyOceana County
StateMichigan
Coordinates43.4761, -86.34397
Functional classRural Principal Arterial - Other

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating85 US tons
Inventory rating50.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length177 ft (53.9 m)
Longest span63 ft (19.2 m)
Deck width44 ft (13.5 m)
Roadway width43 ft (13.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,360 (2007)
Projected traffic7,766 by 2018
Trucks9%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesPedestrian / bicycle
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedDeck replacement with only incidental widening
Estimated improvement cost$163,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was US-31 SB over Hart-Montague Trail built?

It was built in 1974, making it 51 years old in 2025.

What condition is US-31 SB over Hart-Montague Trail 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 November 2023.

How much traffic does US-31 SB over Hart-Montague Trail carry?

About 6,360 vehicles per day (2007 count), of which roughly 9% are trucks.

How long is US-31 SB over Hart-Montague Trail?

The structure is 177 ft (53.9 m) long with a longest span of 63 ft (19.2 m) and a deck 44 ft wide.

Who owns US-31 SB over Hart-Montague Trail?

It is owned by the State Highway Agency.