US Bridges

M-121 over Rush Creek

Fair

Ottawa County, Michigan · 4.9 MI SW of Kent CO Line · Structure no. 000000000008712

Built
1949
76 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
12,246
2007 count
Owner
State
State Highway Agency

About this bridge

M-121 over Rush Creek is a steel stringer/multi-beam or girder carrying M-121 over Rush Creek in Ottawa County, Michigan. It was built in 1949, so it is 76 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 12,246 vehicles a day, roughly 9% of them trucks, projected to reach 18,214 by 2018. The structure is 35 ft (10.6 m) long and 137 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesM-121
CrossesRush Creek
Location4.9 MI SW of Kent CO Line
RouteState Highway 121
CountyOttawa County
StateMichigan
Coordinates42.87003, -85.86224
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.
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.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating80.4 US tons
Inventory rating48.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length35 ft (10.6 m)
Longest span35 ft (10.6 m)
Deck width137 ft (41.7 m)
Roadway width122 ft (37.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,246 (2007)
Projected traffic18,214 by 2018
Trucks9%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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$38,000
NavigationNo navigation control on waterway

Frequently asked questions

When was M-121 over Rush Creek built?

It was built in 1949, making it 76 years old in 2025.

What condition is M-121 over Rush Creek 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 May 2024.

How much traffic does M-121 over Rush Creek carry?

About 12,246 vehicles per day (2007 count), of which roughly 9% are trucks.

How long is M-121 over Rush Creek?

The structure is 35 ft (10.6 m) long with a longest span of 35 ft (10.6 m) and a deck 137 ft wide.

Who owns M-121 over Rush Creek?

It is owned by the State Highway Agency.