Structure 2455 · Emmet County, MI

I-75 S Appr over Huron AVE

Carries I-75 S Appr over Huron AVE, In Mackinaw City.

Overall conditionFair

Set by its lowest-rated component: Substructure at 6 of 9.

How ratings work
Deck7/9 · Good
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT587 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 6/9 · sets the rating

587 ft end to end, longest span 42 ft: about 1.6 football fields. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built195769 years old
Length586.9 ft178.9 m
Daily traffic11,076counted 2007
Last inspectedJuly 2024every 12 months

Location

StateMichigan
CountyEmmet
LocationIn Mackinaw City
CarriesI-75 S Appr
CrossesHuron AVE
Coordinates45.78653, -84.73228

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length586.9 ft (178.9 m)
Max Span42.0 ft (12.8 m)
Deck Width53.8 ft (16.4 m)
Deck Area2934.0 sq m
Main Spans14
Year Built1957

Traffic

Avg Daily Traffic11,076 (2007)
Truck Traffic19%
Lanes On Bridge4
Lanes Under Bridge4

Inspection & Ownership

Last InspectionJuly 2024
Inspection FrequencyEvery 12 months
OwnerState Toll Authority
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number000000000002455

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

Nearby Bridges