US Bridges

M-66 over Whetstone Creek

Fair

Osceola County, Michigan · 4.8 MI N of US-10 · Structure no. 000000000008588

Built
1959
66 years old
Condition
Fair
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
40 ft
1 main span
Daily traffic
1,990
2007 count
Owner
State
State Highway Agency

About this bridge

M-66 over Whetstone Creek is a prestressed concrete box beam or girders - multiple carrying M-66 over Whetstone Creek in Osceola County, Michigan. It was built in 1959, so it is 66 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 6 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 1,990 vehicles a day, roughly 7% of them trucks, projected to reach 2,912 by 2018. The structure is 40 ft (12.2 m) long and 46 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesM-66
CrossesWhetstone Creek
Location4.8 MI N of US-10
RouteState Highway 66
CountyOsceola County
StateMichigan
Coordinates43.97103, -85.14794
Functional classRural Minor Arterial

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 protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating67.1 US tons
Inventory rating40 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 width46 ft (13.9 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,990 (2007)
Projected traffic2,912 by 2018
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 proposedDeck replacement with only incidental widening
Estimated improvement cost$41,000
NavigationNo navigation control on waterway

Frequently asked questions

When was M-66 over Whetstone Creek built?

It was built in 1959, making it 66 years old in 2025.

What condition is M-66 over Whetstone 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 July 2023.

How much traffic does M-66 over Whetstone Creek carry?

About 1,990 vehicles per day (2007 count), of which roughly 7% are trucks.

How long is M-66 over Whetstone Creek?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m) and a deck 46 ft wide.

Who owns M-66 over Whetstone Creek?

It is owned by the State Highway Agency.