US Bridges

I-75 over Cn Gtw & NS Rrs

Fair

Monroe County, Michigan · In Monroe · Structure no. 000000000007172

Built
1954
71 years old, rebuilt 1989
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
170 ft
4 main spans
Daily traffic
63,766
2007 count
Owner
State
State Highway Agency

About this bridge

I-75 over Cn Gtw & NS Rrs is a steel stringer/multi-beam or girder carrying I-75 over Cn Gtw & NS Rrs in Monroe County, Michigan. It was built in 1954 and reconstructed in 1989, so it is 71 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 5 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 63,766 vehicles a day, roughly 23% of them trucks, projected to reach 74,284 by 2018. The structure is 170 ft (51.8 m) long and 116 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesI-75
CrossesCn Gtw & NS Rrs
LocationIn Monroe
RouteInterstate 75
CountyMonroe County
StateMichigan
Coordinates41.89904, -83.374
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating97.9 US tons
Inventory rating58.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length170 ft (51.8 m)
Longest span43 ft (13.1 m)
Deck width116 ft (35.4 m)
Roadway width113 ft (34.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic63,766 (2007)
Projected traffic74,284 by 2018
Trucks23%
Lanes on structure7
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed6.2 mi (10 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 proposedDeck replacement with only incidental widening
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-75 over Cn Gtw & NS Rrs built?

It was built in 1954, making it 71 years old in 2025. It was reconstructed in 1989.

What condition is I-75 over Cn Gtw & NS Rrs 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 August 2023.

How much traffic does I-75 over Cn Gtw & NS Rrs carry?

About 63,766 vehicles per day (2007 count), of which roughly 23% are trucks.

How long is I-75 over Cn Gtw & NS Rrs?

The structure is 170 ft (51.8 m) long with a longest span of 43 ft (13.1 m) and a deck 116 ft wide.

Who owns I-75 over Cn Gtw & NS Rrs?

It is owned by the State Highway Agency.