US Bridges

Plymouth-Annarbor over US-23

Fair

Washtenaw County, Michigan · In Ann Arbor · Structure no. 000000000010873

Built
1962
63 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
285 ft
4 main spans
Daily traffic
10,000
1978 count
Owner
State
State Highway Agency

About this bridge

Plymouth-Annarbor over US-23 is a steel stringer/multi-beam or girder carrying Plymouth-Annarbor over US-23 in Washtenaw County, Michigan. It was built in 1962, so it is 63 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. Its operating status is: open, would be posted or closed except for temporary shoring.

It carries about 10,000 vehicles a day, projected to reach 10,000 by 1977. The structure is 285 ft (86.8 m) long and 64 ft wide.

Location

Open in Google Maps
CarriesPlymouth-Annarbor
CrossesUS-23
LocationIn Ann Arbor
RouteCounty Highway 2006
CountyWashtenaw County
StateMichigan
Coordinates42.30664, -83.68703
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.5 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length285 ft (86.8 m)
Longest span85 ft (25.9 m)
Deck width64 ft (19.5 m)
Roadway width52 ft (15.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,000 (1978)
Projected traffic10,000 by 1977
Trucks—
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 Plymouth-Annarbor over US-23 built?

It was built in 1962, making it 63 years old in 2025.

What condition is Plymouth-Annarbor over US-23 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 April 2024.

How much traffic does Plymouth-Annarbor over US-23 carry?

About 10,000 vehicles per day (1978 count).

How long is Plymouth-Annarbor over US-23?

The structure is 285 ft (86.8 m) long with a longest span of 85 ft (25.9 m) and a deck 64 ft wide.

Who owns Plymouth-Annarbor over US-23?

It is owned by the State Highway Agency.