US Bridges

M-55 over Au Gres River

Good

Iosco County, Michigan · 0.8 MI E of Ogemaw Col · Structure no. 000000000004119

Built
1929
96 years old, rebuilt 1993
Condition
Good
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
34 ft
1 main span
Daily traffic
3,200
2022 count
Owner
State
State Highway Agency

About this bridge

M-55 over Au Gres River is a prestressed concrete stringer/multi-beam or girder carrying M-55 over Au Gres River in Iosco County, Michigan. It was built in 1929 and reconstructed in 1993, so it is 96 years old, older than the Michigan average of 48.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,200 vehicles a day, roughly 9% of them trucks, projected to reach 3,295 by 2042. The structure is 34 ft (10.4 m) long and 39 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesM-55
CrossesAu Gres River
Location0.8 MI E of Ogemaw Col
RouteState Highway 55
CountyIosco County
StateMichigan
Coordinates44.27704, -83.866
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating80.4 US tons
Inventory rating48.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length34 ft (10.4 m)
Longest span33 ft (10.1 m)
Deck width39 ft (12 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2022)
Projected traffic3,295 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

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-55 over Au Gres River built?

It was built in 1929, making it 96 years old in 2025. It was reconstructed in 1993.

What condition is M-55 over Au Gres River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does M-55 over Au Gres River carry?

About 3,200 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is M-55 over Au Gres River?

The structure is 34 ft (10.4 m) long with a longest span of 33 ft (10.1 m) and a deck 39 ft wide.

Who owns M-55 over Au Gres River?

It is owned by the State Highway Agency.