US Bridges

M-57 over Flat River

Good

Montcalm County, Michigan · In Greenville · Structure no. 000000000007431

Built
1948
77 years old, rebuilt 2000
Condition
Good
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
160 ft
3 main spans
Daily traffic
11,727
2007 count
Owner
State
State Highway Agency

About this bridge

M-57 over Flat River is a prestressed concrete box beam or girders - multiple carrying M-57 over Flat River in Montcalm County, Michigan. It was built in 1948 and reconstructed in 2000, so it is 77 years old, older than the Michigan average of 48.3 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 11,727 vehicles a day, roughly 7% of them trucks, projected to reach 13,071 by 2018. The structure is 160 ft (48.7 m) long and 56 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesM-57
CrossesFlat River
LocationIn Greenville
RouteState Highway 57
CountyMontcalm County
StateMichigan
Coordinates43.17751, -85.24773
Functional classUrban Minor Arterial

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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78.9 US tons
Inventory rating45.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length160 ft (48.7 m)
Longest span60 ft (18.2 m)
Deck width56 ft (17 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,727 (2007)
Projected traffic13,071 by 2018
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-57 over Flat River built?

It was built in 1948, making it 77 years old in 2025. It was reconstructed in 2000.

What condition is M-57 over Flat River 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 M-57 over Flat River carry?

About 11,727 vehicles per day (2007 count), of which roughly 7% are trucks.

How long is M-57 over Flat River?

The structure is 160 ft (48.7 m) long with a longest span of 60 ft (18.2 m) and a deck 56 ft wide.

Who owns M-57 over Flat River?

It is owned by the State Highway Agency.