US Bridges

I-75 S Appr over Huron Ave

FairPosted for load

Emmet County, Michigan · In Mackinaw City · Structure no. 000000000002455

Built
1957
68 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
587 ft
14 main spans
Daily traffic
11,076
2007 count
Owner
Toll Authority
State Toll Authority

About this bridge

I-75 S Appr over Huron Ave is a steel stringer/multi-beam or girder carrying I-75 S Appr over Huron Ave in Emmet County, Michigan. It was built in 1957, so it is 68 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 6 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 11,076 vehicles a day, roughly 19% of them trucks, projected to reach 14,257 by 2015. The structure is 587 ft (178.9 m) long and 54 ft wide. If it were closed, the detour would be 124.3 mi (200 km).

Location

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CarriesI-75 S Appr
CrossesHuron Ave
LocationIn Mackinaw City
RouteInterstate 75
CountyEmmet County
StateMichigan
Coordinates45.78653, -84.73228
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.5 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans14
Design loadHS 20
Structure length587 ft (178.9 m)
Longest span42 ft (12.8 m)
Deck width54 ft (16.4 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,076 (2007)
Projected traffic14,257 by 2015
Trucks19%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed124.3 mi (200 km)
TollToll bridge
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Toll Authority
Maintained byState Toll Authority
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 I-75 S Appr over Huron Ave built?

It was built in 1957, making it 68 years old in 2025.

What condition is I-75 S Appr over Huron Ave 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 July 2024.

How much traffic does I-75 S Appr over Huron Ave carry?

About 11,076 vehicles per day (2007 count), of which roughly 19% are trucks.

How long is I-75 S Appr over Huron Ave?

The structure is 587 ft (178.9 m) long with a longest span of 42 ft (12.8 m) and a deck 54 ft wide.

Who owns I-75 S Appr over Huron Ave?

It is owned by the State Toll Authority.