US Bridges

M-50 over S Br Macon River

Fair

Monroe County, Michigan · 2.5 MI W of Dundee · Structure no. 000000000007113

Built
1953
72 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
55 ft
1 main span
Daily traffic
6,646
2007 count
Owner
State
State Highway Agency

About this bridge

M-50 over S Br Macon River is a steel stringer/multi-beam or girder carrying M-50 over S Br Macon River in Monroe County, Michigan. It was built in 1953, so it is 72 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 6,646 vehicles a day, roughly 6% of them trucks, projected to reach 12,805 by 2018. The structure is 55 ft (16.7 m) long and 43 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesM-50
CrossesS Br Macon River
Location2.5 MI W of Dundee
RouteState Highway 50
CountyMonroe County
StateMichigan
Coordinates41.96541, -83.70705
Functional classRural Minor 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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating80 US tons
Inventory rating47.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length55 ft (16.7 m)
Longest span55 ft (16.7 m)
Deck width43 ft (13.2 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,646 (2007)
Projected traffic12,805 by 2018
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedDeck replacement with only incidental widening
Estimated improvement cost$50,000
NavigationNo navigation control on waterway

Frequently asked questions

When was M-50 over S Br Macon River built?

It was built in 1953, making it 72 years old in 2025.

What condition is M-50 over S Br Macon River 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 August 2023.

How much traffic does M-50 over S Br Macon River carry?

About 6,646 vehicles per day (2007 count), of which roughly 6% are trucks.

How long is M-50 over S Br Macon River?

The structure is 55 ft (16.7 m) long with a longest span of 55 ft (16.7 m) and a deck 43 ft wide.

Who owns M-50 over S Br Macon River?

It is owned by the State Highway Agency.