US Bridges

Musson Road over Flat River

FairPosted for load

Montcalm County, Michigan · 0.25 MI N of CO 544 · Structure no. 000000000007483

Built
1978
47 years old
Condition
Fair
inspected March 2023
Type
Slab
Wood or Timber
Length
32 ft
1 main span
Daily traffic
577
2003 count
Owner
County
County Highway Agency

About this bridge

Musson Road over Flat River is a wood or timber slab carrying Musson Road over Flat River in Montcalm County, Michigan. It was built in 1978, so it is 47 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. Its operating status is: posted for load restriction.

It carries about 577 vehicles a day, roughly 5% of them trucks, projected to reach 753 by 2023. The structure is 32 ft (9.7 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesMusson Road
CrossesFlat River
Location0.25 MI N of CO 544
RouteCounty Highway 0
CountyMontcalm County
StateMichigan
Coordinates43.43469, -85.12669
Functional classRural Local

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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.8 US tons
Inventory rating24.7 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20 + Mod
Structure length32 ft (9.7 m)
Longest span30 ft (9.1 m)
Deck width26 ft (7.9 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic577 (2003)
Projected traffic753 by 2023
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Musson Road over Flat River built?

It was built in 1978, making it 47 years old in 2025.

What condition is Musson Road over Flat River 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 March 2023.

How much traffic does Musson Road over Flat River carry?

About 577 vehicles per day (2003 count), of which roughly 5% are trucks.

How long is Musson Road over Flat River?

The structure is 32 ft (9.7 m) long with a longest span of 30 ft (9.1 m) and a deck 26 ft wide.

Who owns Musson Road over Flat River?

It is owned by the County Highway Agency.