US Bridges

US-23 NB over US-23 Br

Poor

Washtenaw County, Michigan · 0.1 MI E of Ann Arbor Ex · Structure no. 000000000010867

Built
1962
63 years old
Condition
Poor
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
188 ft
4 main spans
Daily traffic
39,120
2007 count
Owner
State
State Highway Agency

About this bridge

US-23 NB over US-23 Br is a prestressed concrete stringer/multi-beam or girder carrying US-23 NB over US-23 Br 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 poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: open, would be posted or closed except for temporary shoring.

It carries about 39,120 vehicles a day, roughly 9% of them trucks, projected to reach 36,802 by 2018. The structure is 188 ft (57.3 m) long and 57 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesUS-23 NB
CrossesUS-23 Br
Location0.1 MI E of Ann Arbor Ex
RouteU.S. Route 23
Coordinates42.25459, -83.68366
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 12 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating62.2 US tons
Inventory rating37.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length188 ft (57.3 m)
Longest span55 ft (16.7 m)
Deck width57 ft (17.4 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic39,120 (2007)
Projected traffic36,802 by 2018
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

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 US-23 NB over US-23 Br built?

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

What condition is US-23 NB over US-23 Br in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in May 2024.

How much traffic does US-23 NB over US-23 Br carry?

About 39,120 vehicles per day (2007 count), of which roughly 9% are trucks.

How long is US-23 NB over US-23 Br?

The structure is 188 ft (57.3 m) long with a longest span of 55 ft (16.7 m) and a deck 57 ft wide.

Who owns US-23 NB over US-23 Br?

It is owned by the State Highway Agency.