US Bridges

M-6 Ramp a over I-96 & Thornapple River

Fair

Kent County, Michigan · Cascade Twp Sec 22 · Structure no. 000000000012901

Built
2001
24 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
1,204 ft
6 main spans
Daily traffic
11,894
2023 count
Owner
State
State Highway Agency

About this bridge

M-6 Ramp a over I-96 & Thornapple River is a steel continuous stringer/multi-beam or girder carrying M-6 Ramp a over I-96 & Thornapple River in Kent County, Michigan. It was built in 2001, so it is 24 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 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 11,894 vehicles a day, roughly 13% of them trucks. The structure is 1,204 ft (367.1 m) long and 50 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesM-6 Ramp a
CrossesI-96 & Thornapple River
LocationCascade Twp Sec 22
RouteState Highway 6
CountyKent County
StateMichigan
Coordinates42.88876, -85.48594
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 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 geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating38.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 25 or greater
Structure length1,204 ft (367.1 m)
Longest span231 ft (70.3 m)
Deck width50 ft (15.2 m)
Roadway width46 ft (14.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,894 (2023)
Projected traffic—
Trucks13%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
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-6 Ramp a over I-96 & Thornapple River built?

It was built in 2001, making it 24 years old in 2025.

What condition is M-6 Ramp a over I-96 & Thornapple 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 November 2024.

How much traffic does M-6 Ramp a over I-96 & Thornapple River carry?

About 11,894 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is M-6 Ramp a over I-96 & Thornapple River?

The structure is 1,204 ft (367.1 m) long with a longest span of 231 ft (70.3 m) and a deck 50 ft wide.

Who owns M-6 Ramp a over I-96 & Thornapple River?

It is owned by the State Highway Agency.