US Bridges

US-31 NB over I-75 NB

Fair

Cheboygan County, Michigan · @ I-75 US-31 JCT · Structure no. 000000000001519

Built
1959
66 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Concrete Continuous
Length
311 ft
4 main spans
Daily traffic
1,661
2007 count
Owner
State
State Highway Agency

About this bridge

US-31 NB over I-75 NB is a concrete continuous tee beam carrying US-31 NB over I-75 NB in Cheboygan 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 1,661 vehicles a day, roughly 9% of them trucks, projected to reach 2,631 by 2018. The structure is 311 ft (94.8 m) long and 37 ft wide.

Location

Open in Google Maps
CarriesUS-31 NB
CrossesI-75 NB
Location@ I-75 US-31 JCT
RouteU.S. Route 31
CountyCheboygan County
StateMichigan
Coordinates45.73299, -84.72831
Functional classRural Principal Arterial - Other

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.8 US tons
Inventory rating40 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length311 ft (94.8 m)
Longest span97 ft (29.7 m)
Deck width37 ft (11.4 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,661 (2007)
Projected traffic2,631 by 2018
Trucks9%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes

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 US-31 NB over I-75 NB built?

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

What condition is US-31 NB over I-75 NB 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 2023.

How much traffic does US-31 NB over I-75 NB carry?

About 1,661 vehicles per day (2007 count), of which roughly 9% are trucks.

How long is US-31 NB over I-75 NB?

The structure is 311 ft (94.8 m) long with a longest span of 97 ft (29.7 m) and a deck 37 ft wide.

Who owns US-31 NB over I-75 NB?

It is owned by the State Highway Agency.