US Bridges

I-69 NB over Thornapple River

Fair

Eaton County, Michigan · 0.4 MI SW of Potterville · Structure no. 000000000002262

Built
1989
36 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
62 ft
1 main span
Daily traffic
14,585
2007 count
Owner
State
State Highway Agency

About this bridge

I-69 NB over Thornapple River is a prestressed concrete stringer/multi-beam or girder carrying I-69 NB over Thornapple River in Eaton County, Michigan. It was built in 1989, so it is 36 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 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 14,585 vehicles a day, roughly 18% of them trucks, projected to reach 18,576 by 2018. The structure is 62 ft (18.9 m) long and 47 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesI-69 NB
CrossesThornapple River
Location0.4 MI SW of Potterville
RouteInterstate 69
CountyEaton County
StateMichigan
Coordinates42.61512, -84.7496
Functional classRural Principal Arterial - Interstate

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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating46.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length62 ft (18.9 m)
Longest span61 ft (18.5 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,585 (2007)
Projected traffic18,576 by 2018
Trucks18%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-69 NB over Thornapple River built?

It was built in 1989, making it 36 years old in 2025.

What condition is I-69 NB over Thornapple 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 June 2023.

How much traffic does I-69 NB over Thornapple River carry?

About 14,585 vehicles per day (2007 count), of which roughly 18% are trucks.

How long is I-69 NB over Thornapple River?

The structure is 62 ft (18.9 m) long with a longest span of 61 ft (18.5 m) and a deck 47 ft wide.

Who owns I-69 NB over Thornapple River?

It is owned by the State Highway Agency.