US Bridges

Six Lakes Road over Flat River

Good

Montcalm County, Michigan · 1.0 MI S of M-46 · Structure no. 000000000007482

Built
2017
8 years old
Condition
Good
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
65 ft
1 main span
Daily traffic
292
2016 count
Owner
County
County Highway Agency

About this bridge

Six Lakes Road over Flat River is a prestressed concrete box beam or girders - multiple carrying Six Lakes Road over Flat River in Montcalm County, Michigan. It was built in 2017, so it is 8 years old, younger 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 292 vehicles a day, roughly 2% of them trucks, projected to reach 356 by 2036. The structure is 65 ft (19.8 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesSix Lakes Road
CrossesFlat River
Location1.0 MI S of M-46
RouteCounty Highway 0
CountyMontcalm County
StateMichigan
Coordinates43.4139, -85.149
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating82.9 US tons
Inventory rating63.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadGreater than HL 93
Structure length65 ft (19.8 m)
Longest span63 ft (19.1 m)
Deck width31 ft (9.6 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic292 (2016)
Projected traffic356 by 2036
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Six Lakes Road over Flat River built?

It was built in 2017, making it 8 years old in 2025.

What condition is Six Lakes Road 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 September 2023.

How much traffic does Six Lakes Road over Flat River carry?

About 292 vehicles per day (2016 count), of which roughly 2% are trucks.

How long is Six Lakes Road over Flat River?

The structure is 65 ft (19.8 m) long with a longest span of 63 ft (19.1 m) and a deck 31 ft wide.

Who owns Six Lakes Road over Flat River?

It is owned by the County Highway Agency.