US Bridges

Isabella Road over Chippewa River

Fair

Isabella County, Michigan · 0.5 M N SE Cor Sec 2 T14N · Structure no. 000000000004318

Built
1972
53 years old
Condition
Fair
inspected April 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
154 ft
3 main spans
Daily traffic
1,330
2002 count
Owner
County
County Highway Agency

About this bridge

Isabella Road over Chippewa River is a prestressed concrete box beam or girders - multiple carrying Isabella Road over Chippewa River in Isabella County, Michigan. It was built in 1972, so it is 53 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 1,330 vehicles a day, projected to reach 1,975 by 2022. The structure is 154 ft (46.9 m) long and 33 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesIsabella Road
CrossesChippewa River
Location0.5 M N SE Cor Sec 2 T14N
RouteCounty Highway 3748
CountyIsabella County
StateMichigan
Coordinates43.63465, -84.74818
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating62.7 US tons
Inventory rating37.6 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadH 20
Structure length154 ft (46.9 m)
Longest span53 ft (16.1 m)
Deck width33 ft (10.1 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,330 (2002)
Projected traffic1,975 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 Isabella Road over Chippewa River built?

It was built in 1972, making it 53 years old in 2025.

What condition is Isabella Road over Chippewa 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 April 2024.

How much traffic does Isabella Road over Chippewa River carry?

About 1,330 vehicles per day (2002 count).

How long is Isabella Road over Chippewa River?

The structure is 154 ft (46.9 m) long with a longest span of 53 ft (16.1 m) and a deck 33 ft wide.

Who owns Isabella Road over Chippewa River?

It is owned by the County Highway Agency.