US Bridges

I-75 over M-85 (fort St)

Fair

Wayne County, Michigan · In Detroit · Structure no. 000000000011733

Built
1967
58 years old, rebuilt 2002
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
299 ft
2 main spans
Daily traffic
105,854
2007 count
Owner
State
State Highway Agency

About this bridge

I-75 over M-85 (fort St) is a steel continuous stringer/multi-beam or girder carrying I-75 over M-85 (fort St) in Wayne County, Michigan. It was built in 1967 and reconstructed in 2002, so it is 58 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.

It carries about 105,854 vehicles a day, roughly 12% of them trucks, projected to reach 104,504 by 2018. The structure is 299 ft (91.1 m) long and 154 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesI-75
CrossesM-85 (fort St)
LocationIn Detroit
RouteInterstate 75
CountyWayne County
StateMichigan
Coordinates42.27836, -83.15341
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.4 US tons
Inventory rating45.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 25 or greater
Structure length299 ft (91.1 m)
Longest span108 ft (32.9 m)
Deck width154 ft (46.8 m)
Roadway width147 ft (44.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic105,854 (2007)
Projected traffic104,504 by 2018
Trucks12%
Lanes on structure9
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-75 over M-85 (fort St) built?

It was built in 1967, making it 58 years old in 2025. It was reconstructed in 2002.

What condition is I-75 over M-85 (fort St) 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 June 2023.

How much traffic does I-75 over M-85 (fort St) carry?

About 105,854 vehicles per day (2007 count), of which roughly 12% are trucks.

How long is I-75 over M-85 (fort St)?

The structure is 299 ft (91.1 m) long with a longest span of 108 ft (32.9 m) and a deck 154 ft wide.

Who owns I-75 over M-85 (fort St)?

It is owned by the State Highway Agency.