US Bridges

Chippewa Road over Onion Creek

FairPosted for load

Isabella County, Michigan · Sec 25-26 Chippewa Twp · Structure no. 000000000004322

Built
1980
45 years old
Condition
Fair
inspected May 2024
Type
Slab
Wood or Timber
Length
24 ft
1 main span
Daily traffic
185
2002 count
Owner
County
County Highway Agency

About this bridge

Chippewa Road over Onion Creek is a wood or timber slab carrying Chippewa Road over Onion Creek in Isabella County, Michigan. It was built in 1980, so it is 45 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. Its operating status is: posted for load restriction.

It carries about 185 vehicles a day, projected to reach 225 by 2022. The structure is 24 ft (7.3 m) long and 31 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesChippewa Road
CrossesOnion Creek
LocationSec 25-26 Chippewa Twp
RouteCounty Highway 0
CountyIsabella County
StateMichigan
Coordinates43.57214, -84.62784
Functional classRural Local

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.
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 inspectionMay 2024
Inspection intervalevery 24 months
Operating statusPosted for load 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 alignment8: Equal to present desirable criteria
Operating rating45.2 US tons
Inventory rating30.9 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span22 ft (6.7 m)
Deck width31 ft (9.6 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic185 (2002)
Projected traffic225 by 2022
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Chippewa Road over Onion Creek built?

It was built in 1980, making it 45 years old in 2025.

What condition is Chippewa Road over Onion 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 2024.

How much traffic does Chippewa Road over Onion Creek carry?

About 185 vehicles per day (2002 count).

How long is Chippewa Road over Onion Creek?

The structure is 24 ft (7.3 m) long with a longest span of 22 ft (6.7 m) and a deck 31 ft wide.

Who owns Chippewa Road over Onion Creek?

It is owned by the County Highway Agency.