US Bridges

M-120 SB over N Channel Muskegon River

Fair

Muskegon County, Michigan · In N Muskegon · Structure no. 000000000007612

Built
1996
29 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
305 ft
3 main spans
Daily traffic
13,641
2007 count
Owner
State
State Highway Agency

About this bridge

M-120 SB over N Channel Muskegon River is a prestressed concrete stringer/multi-beam or girder carrying M-120 SB over N Channel Muskegon River in Muskegon County, Michigan. It was built in 1996, so it is 29 years old, younger 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 13,641 vehicles a day, roughly 3% of them trucks, projected to reach 14,941 by 2018. The structure is 305 ft (92.9 m) long and 58 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesM-120 SB
CrossesN Channel Muskegon River
LocationIn N Muskegon
RouteState Highway 120
CountyMuskegon County
StateMichigan
Coordinates43.26186, -86.24637
Functional classUrban Other Principal 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating81.8 US tons
Inventory rating45.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length305 ft (92.9 m)
Longest span106 ft (32.3 m)
Deck width58 ft (17.6 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,641 (2007)
Projected traffic14,941 by 2018
Trucks3%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-120 SB over N Channel Muskegon River built?

It was built in 1996, making it 29 years old in 2025.

What condition is M-120 SB over N Channel Muskegon 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 July 2023.

How much traffic does M-120 SB over N Channel Muskegon River carry?

About 13,641 vehicles per day (2007 count), of which roughly 3% are trucks.

How long is M-120 SB over N Channel Muskegon River?

The structure is 305 ft (92.9 m) long with a longest span of 106 ft (32.3 m) and a deck 58 ft wide.

Who owns M-120 SB over N Channel Muskegon River?

It is owned by the State Highway Agency.