US Bridges

Johnson Road over Flat River

Fair

Montcalm County, Michigan · 1.25 North of Wise Road · Structure no. 000000000007454

Built
1985
40 years old
Condition
Fair
inspected September 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
90 ft
2 main spans
Daily traffic
1,082
2017 count
Owner
County
County Highway Agency

About this bridge

Johnson Road over Flat River is a prestressed concrete box beam or girders - multiple carrying Johnson Road over Flat River in Montcalm County, Michigan. It was built in 1985, so it is 40 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 5 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 1,082 vehicles a day, projected to reach 1,374 by 2039. The structure is 90 ft (27.4 m) long and 37 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesJohnson Road
CrossesFlat River
Location1.25 North of Wise Road
RouteCounty Highway 5939
CountyMontcalm County
StateMichigan
Coordinates43.22561, -85.30221
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadHS 20 + Mod
Structure length90 ft (27.4 m)
Longest span45 ft (13.7 m)
Deck width37 ft (11.3 m)
Roadway width35 ft (10.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,082 (2017)
Projected traffic1,374 by 2039
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 Johnson Road over Flat River built?

It was built in 1985, making it 40 years old in 2025.

What condition is Johnson 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 September 2024.

How much traffic does Johnson Road over Flat River carry?

About 1,082 vehicles per day (2017 count).

How long is Johnson Road over Flat River?

The structure is 90 ft (27.4 m) long with a longest span of 45 ft (13.7 m) and a deck 37 ft wide.

Who owns Johnson Road over Flat River?

It is owned by the County Highway Agency.