US Bridges

M-46 (exten) over US-131

Fair

Montcalm County, Michigan · 2.5 MI NW of Howard City · Structure no. 000000000007427

Built
1979
46 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
368 ft
3 main spans
Daily traffic
6,427
2007 count
Owner
State
State Highway Agency

About this bridge

M-46 (exten) over US-131 is a steel stringer/multi-beam or girder carrying M-46 (exten) over US-131 in Montcalm County, Michigan. It was built in 1979, so it is 46 years old, younger 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 6,427 vehicles a day, roughly 18% of them trucks, projected to reach 8,233 by 2018. The structure is 368 ft (112.2 m) long and 52 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesM-46 (exten)
CrossesUS-131
Location2.5 MI NW of Howard City
RouteState Highway 46
CountyMontcalm County
StateMichigan
Coordinates43.42483, -85.49552
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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating86.1 US tons
Inventory rating51.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length368 ft (112.2 m)
Longest span124 ft (37.8 m)
Deck width52 ft (15.8 m)
Roadway width49 ft (15 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,427 (2007)
Projected traffic8,233 by 2018
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
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$192,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was M-46 (exten) over US-131 built?

It was built in 1979, making it 46 years old in 2025.

What condition is M-46 (exten) over US-131 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 October 2023.

How much traffic does M-46 (exten) over US-131 carry?

About 6,427 vehicles per day (2007 count), of which roughly 18% are trucks.

How long is M-46 (exten) over US-131?

The structure is 368 ft (112.2 m) long with a longest span of 124 ft (37.8 m) and a deck 52 ft wide.

Who owns M-46 (exten) over US-131?

It is owned by the State Highway Agency.