US Bridges

M-28 over M Br Ontonagon River

Fair

Ontonagon County, Michigan · 5.0 MI W of Houghton Col · Structure no. 000000000008491

Built
1929
96 years old, rebuilt 1992
Condition
Fair
inspected June 2024
Type
Arch - Deck
Steel
Length
193 ft
1 main span
Daily traffic
2,303
2007 count
Owner
State
State Highway Agency

About this bridge

M-28 over M Br Ontonagon River is a steel arch - deck carrying M-28 over M Br Ontonagon River in Ontonagon County, Michigan. It was built in 1929 and reconstructed in 1992, 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 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 2,303 vehicles a day, roughly 18% of them trucks, projected to reach 1,668 by 2018. The structure is 193 ft (58.8 m) long and 35 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesM-28
CrossesM Br Ontonagon River
Location5.0 MI W of Houghton Col
RouteState Highway 28
CountyOntonagon County
StateMichigan
Coordinates46.47927, -89.09045
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating67.1 US tons
Inventory rating40.3 US tons

Structure

Structure typeArch - Deck
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadHS 25 or greater
Structure length193 ft (58.8 m)
Longest span150 ft (45.7 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,303 (2007)
Projected traffic1,668 by 2018
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedDeck replacement with only incidental widening
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-28 over M Br Ontonagon River built?

It was built in 1929, making it 96 years old in 2025. It was reconstructed in 1992.

What condition is M-28 over M Br Ontonagon 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 June 2024.

How much traffic does M-28 over M Br Ontonagon River carry?

About 2,303 vehicles per day (2007 count), of which roughly 18% are trucks.

How long is M-28 over M Br Ontonagon River?

The structure is 193 ft (58.8 m) long with a longest span of 150 ft (45.7 m) and a deck 35 ft wide.

Who owns M-28 over M Br Ontonagon River?

It is owned by the State Highway Agency.