US Bridges

M-21 over Stoney Creek

Fair

Ionia County, Michigan · 1.5 MI E of Muir · Structure no. 000000000004012

Built
1929
96 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
100 ft
2 main spans
Daily traffic
2,533
2007 count
Owner
State
State Highway Agency

About this bridge

M-21 over Stoney Creek is a steel stringer/multi-beam or girder carrying M-21 over Stoney Creek in Ionia County, Michigan. It was built in 1929, so it is 96 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 2,533 vehicles a day, roughly 13% of them trucks, projected to reach 3,388 by 2018. The structure is 100 ft (30.5 m) long and 46 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesM-21
CrossesStoney Creek
Location1.5 MI E of Muir
RouteState Highway 21
CountyIonia County
StateMichigan
Coordinates42.99954, -84.90808
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.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60 US tons
Inventory rating31.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length100 ft (30.5 m)
Longest span50 ft (15.2 m)
Deck width46 ft (14 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,533 (2007)
Projected traffic3,388 by 2018
Trucks13%
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

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$118,000
NavigationNo navigation control on waterway

Frequently asked questions

When was M-21 over Stoney Creek built?

It was built in 1929, making it 96 years old in 2025.

What condition is M-21 over Stoney 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 October 2024.

How much traffic does M-21 over Stoney Creek carry?

About 2,533 vehicles per day (2007 count), of which roughly 13% are trucks.

How long is M-21 over Stoney Creek?

The structure is 100 ft (30.5 m) long with a longest span of 50 ft (15.2 m) and a deck 46 ft wide.

Who owns M-21 over Stoney Creek?

It is owned by the State Highway Agency.