I-75 over Straits Of Mackinac

Fair Condition69 years old11,926 vehicles/day

Location

StateMichigan
CountyEmmet
LocationMackinaw City-st Ignace
CarriesI-75
CrossesStraits Of Mackinac
Coordinates45.83684, -84.72481

Condition Ratings

Overall ConditionFair
Deck6 (Satisfactory)
Superstructure6 (Satisfactory)
Substructure7 (Good)
Channel/Waterway9 (Excellent)
Scour Critical8 — Stable, low risk

Physical Characteristics

MaterialSteel
DesignSuspension
Total Length19247.7 ft (5866.7 m)
Max Span3800.9 ft (1158.5 m)
Deck Width53.8 ft (16.4 m)
Deck Area96213.9 sq m
Main Spans3
Year Built1957

Traffic

Avg Daily Traffic11,926 (2021)
Truck Traffic7%
Lanes On Bridge4

Inspection & Ownership

Last Inspection724
Inspection FrequencyEvery 12 months
OwnerState Toll Authority
Historical SignificanceBridge is on the National Register of Historic Places
Structure Number000000000002456

Nearby Bridges

I-75 N Appr over Straits Of Mackinac 0.6 mi Fair Us-2|i-75 Bl over I-75 NB 1.4 mi Fair I-75 NB over Portage ST 2.1 mi Fair I-75 SB over Portage ST 2.1 mi Fair I-75 NB over Cheeseman RD 2.9 mi Poor I-75 SB over Cheeseman RD 2.9 mi Poor I-75 S Appr over Huron AVE 3.5 mi Fair I-75 NB over Central ST 3.8 mi Fair I-75 NB over D&m Rr (abn) 3.9 mi Fair Us-23 SB over I-75 NB 4.5 mi Good