US Bridges

M-153 Conn Ramp B over M-14

Fair

Washtenaw County, Michigan · 9.0 MI SW of Plymouth · Structure no. 000000000010921

Built
1975
50 years old, rebuilt 2006
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
333 ft
4 main spans
Daily traffic
6,694
2007 count
Owner
State
State Highway Agency

About this bridge

M-153 Conn Ramp B over M-14 is a steel stringer/multi-beam or girder carrying M-153 Conn Ramp B over M-14 in Washtenaw County, Michigan. It was built in 1975 and reconstructed in 2006, so it is 50 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 6,694 vehicles a day, roughly 4% of them trucks, projected to reach 6,793 by 2018. The structure is 333 ft (101.5 m) long and 45 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesM-153 Conn Ramp B
CrossesM-14
Location9.0 MI SW of Plymouth
RouteState Highway 153
CountyWashtenaw County
StateMichigan
Coordinates42.32687, -83.63179
Functional classRural Principal Arterial - Other

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating85.8 US tons
Inventory rating46.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 25 or greater
Structure length333 ft (101.5 m)
Longest span128 ft (39 m)
Deck width45 ft (13.6 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,694 (2007)
Projected traffic6,793 by 2018
Trucks4%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was M-153 Conn Ramp B over M-14 built?

It was built in 1975, making it 50 years old in 2025. It was reconstructed in 2006.

What condition is M-153 Conn Ramp B over M-14 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 September 2024.

How much traffic does M-153 Conn Ramp B over M-14 carry?

About 6,694 vehicles per day (2007 count), of which roughly 4% are trucks.

How long is M-153 Conn Ramp B over M-14?

The structure is 333 ft (101.5 m) long with a longest span of 128 ft (39 m) and a deck 45 ft wide.

Who owns M-153 Conn Ramp B over M-14?

It is owned by the State Highway Agency.