US Bridges

M-48 over Big Munuscong River

Fair

Chippewa County, Michigan · 2.9 MI E of I-75 · Structure no. 000000000001588

Built
1955
70 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
146 ft
3 main spans
Daily traffic
605
2007 count
Owner
State
State Highway Agency

About this bridge

M-48 over Big Munuscong River is a steel stringer/multi-beam or girder carrying M-48 over Big Munuscong River in Chippewa County, Michigan. It was built in 1955, so it is 70 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 605 vehicles a day, roughly 27% of them trucks, projected to reach 476 by 2018. The structure is 146 ft (44.5 m) long and 35 ft wide. If it were closed, the detour would be 34.8 mi (56 km).

Location

Open in Google Maps
CarriesM-48
CrossesBig Munuscong River
Location2.9 MI E of I-75
RouteState Highway 48
CountyChippewa County
StateMichigan
Coordinates46.1872, -84.49763
Functional classRural Major Collector

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating64.3 US tons
Inventory rating38.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length146 ft (44.5 m)
Longest span48 ft (14.7 m)
Deck width35 ft (10.8 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic605 (2007)
Projected traffic476 by 2018
Trucks27%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 km)
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-48 over Big Munuscong River built?

It was built in 1955, making it 70 years old in 2025.

What condition is M-48 over Big Munuscong River 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 October 2024.

How much traffic does M-48 over Big Munuscong River carry?

About 605 vehicles per day (2007 count), of which roughly 27% are trucks.

How long is M-48 over Big Munuscong River?

The structure is 146 ft (44.5 m) long with a longest span of 48 ft (14.7 m) and a deck 35 ft wide.

Who owns M-48 over Big Munuscong River?

It is owned by the State Highway Agency.