US Bridges

M-46 over Bush Creek

Fair

Gratiot County, Michigan · 3.5 MI E of ST Louis · Structure no. 000000000003130

Built
1960
65 years old
Condition
Fair
inspected May 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
40 ft
1 main span
Daily traffic
5,784
2007 count
Owner
State
State Highway Agency

About this bridge

M-46 over Bush Creek is a prestressed concrete box beam or girders - multiple carrying M-46 over Bush Creek in Gratiot County, Michigan. It was built in 1960, so it is 65 years old, older 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 5,784 vehicles a day, roughly 8% of them trucks, projected to reach 5,919 by 2018. The structure is 40 ft (12.2 m) long and 37 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesM-46
CrossesBush Creek
Location3.5 MI E of ST Louis
RouteState Highway 46
CountyGratiot County
StateMichigan
Coordinates43.40801, -84.53708
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
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 protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating82.1 US tons
Inventory rating49.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length40 ft (12.2 m)
Longest span40 ft (12.2 m)
Deck width37 ft (11.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,784 (2007)
Projected traffic5,919 by 2018
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-46 over Bush Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is M-46 over Bush Creek 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 May 2023.

How much traffic does M-46 over Bush Creek carry?

About 5,784 vehicles per day (2007 count), of which roughly 8% are trucks.

How long is M-46 over Bush Creek?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m) and a deck 37 ft wide.

Who owns M-46 over Bush Creek?

It is owned by the State Highway Agency.