US Bridges

M-66 NB over I-96

Fair

Ionia County, Michigan · @ M-66 · Structure no. 000000000003985

Built
1959
66 years old
Condition
Fair
inspected October 2024
Type
Tee Beam
Concrete Continuous
Length
268 ft
4 main spans
Daily traffic
10,500
2016 count
Owner
State
State Highway Agency

About this bridge

M-66 NB over I-96 is a concrete continuous tee beam carrying M-66 NB over I-96 in Ionia 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 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 10,500 vehicles a day, roughly 7% of them trucks, projected to reach 11,600 by 2036. The structure is 268 ft (81.8 m) long and 36 ft wide.

Location

Open in Google Maps
CarriesM-66 NB
CrossesI-96
Location@ M-66
RouteState Highway 66
CountyIonia County
StateMichigan
Coordinates42.87936, -85.07481
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.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating70.3 US tons
Inventory rating41.8 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length268 ft (81.8 m)
Longest span81 ft (24.6 m)
Deck width36 ft (11 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,500 (2016)
Projected traffic11,600 by 2036
Trucks7%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was M-66 NB over I-96 built?

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

What condition is M-66 NB over I-96 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-66 NB over I-96 carry?

About 10,500 vehicles per day (2016 count), of which roughly 7% are trucks.

How long is M-66 NB over I-96?

The structure is 268 ft (81.8 m) long with a longest span of 81 ft (24.6 m) and a deck 36 ft wide.

Who owns M-66 NB over I-96?

It is owned by the State Highway Agency.