US Bridges

I-94 over Aa RR

Fair

Washtenaw County, Michigan · In Ann Arbor · Structure no. 000000000010830

Built
1954
71 years old, rebuilt 1975
Condition
Fair
inspected June 2024
Type
Tee Beam
Concrete
Length
130 ft
3 main spans
Daily traffic
78,348
2007 count
Owner
State
State Highway Agency

About this bridge

I-94 over Aa RR is a concrete tee beam carrying I-94 over Aa RR in Washtenaw County, Michigan. It was built in 1954 and reconstructed in 1975, so it is 71 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 78,348 vehicles a day, roughly 12% of them trucks, projected to reach 90,534 by 2018. The structure is 130 ft (39.5 m) long and 96 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesI-94
CrossesAa RR
LocationIn Ann Arbor
RouteInterstate 94
CountyWashtenaw County
StateMichigan
Coordinates42.23713, -83.73074
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating75.4 US tons
Inventory rating45 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length130 ft (39.5 m)
Longest span41 ft (12.6 m)
Deck width96 ft (29.3 m)
Roadway width94 ft (28.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic78,348 (2007)
Projected traffic90,534 by 2018
Trucks12%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-94 over Aa RR built?

It was built in 1954, making it 71 years old in 2025. It was reconstructed in 1975.

What condition is I-94 over Aa RR 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 June 2024.

How much traffic does I-94 over Aa RR carry?

About 78,348 vehicles per day (2007 count), of which roughly 12% are trucks.

How long is I-94 over Aa RR?

The structure is 130 ft (39.5 m) long with a longest span of 41 ft (12.6 m) and a deck 96 ft wide.

Who owns I-94 over Aa RR?

It is owned by the State Highway Agency.