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I-75 NB over Mackinac Trail

Mackinac County, Michigan · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

I-75 NB over Mackinac Trail in Mackinac County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
It was built in 1963, making it 62 years old at the 2025 inventory.
It carries about 2,039 vehicles a day (traffic count year 2007).
Its listed owner is the state highway agency.
It is one of 36 of the 63 inventoried bridges in Mackinac County rated fair (57.1%); 10 (15.9%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Steel stringer or multi-beam girder
Length	about 120 ft
Location	4.0 Mi NE of M-123
NBI structure number	000000000005957
Condition class	Fair

Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.

Bridge	Built	Vehicles/day	Condition
Us-2\|i-75 Bl over I-75 NB	1957	7,550	Fair
US-2 over Cut River	1947	4,450	Fair
US-2 over Brevort River	2019	4,400	Good
I-75 SB over Carp River	1964	4,400	Fair
I-75 SB over Mackinac Trail	1963	4,400	Fair
I-75 Bl over I-75 NB	1960	4,350	Fair