US Bridges

I-75BL|M-18|N Rosc over I-75 NB

Fair

Roscommon County, Michigan · 2.0 MI S of Roscommon · Structure no. 000000000009025

Built
1971
54 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
484 ft
7 main spans
Daily traffic
2,961
2018 count
Owner
State
State Highway Agency

About this bridge

I-75BL|M-18|N Rosc over I-75 NB is a steel stringer/multi-beam or girder carrying I-75BL|M-18|N Rosc over I-75 NB in Roscommon County, Michigan. It was built in 1971, so it is 54 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 2,961 vehicles a day, roughly 5% of them trucks, projected to reach 3,405 by 2038. The structure is 484 ft (147.4 m) long and 51 ft wide.

Location

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CarriesI-75BL|M-18|N Rosc
CrossesI-75 NB
Location2.0 MI S of Roscommon
RouteState Highway 18
CountyRoscommon County
StateMichigan
Coordinates44.45822, -84.6047
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionAugust 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 alignment6: Equal to present minimum criteria
Operating rating69.3 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadHS 20
Structure length484 ft (147.4 m)
Longest span94 ft (28.5 m)
Deck width51 ft (15.4 m)
Roadway width47 ft (14.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,961 (2018)
Projected traffic3,405 by 2038
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemNo

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-75BL|M-18|N Rosc over I-75 NB built?

It was built in 1971, making it 54 years old in 2025.

What condition is I-75BL|M-18|N Rosc over I-75 NB 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-75BL|M-18|N Rosc over I-75 NB carry?

About 2,961 vehicles per day (2018 count), of which roughly 5% are trucks.

How long is I-75BL|M-18|N Rosc over I-75 NB?

The structure is 484 ft (147.4 m) long with a longest span of 94 ft (28.5 m) and a deck 51 ft wide.

Who owns I-75BL|M-18|N Rosc over I-75 NB?

It is owned by the State Highway Agency.