US Bridges

M-15 over Cass River

Good

Tuscola County, Michigan · In Vassar · Structure no. 000000000010410

Built
2015
10 years old
Condition
Good
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
310 ft
3 main spans
Daily traffic
14,550
2013 count
Owner
State
State Highway Agency

About this bridge

M-15 over Cass River is a steel continuous stringer/multi-beam or girder carrying M-15 over Cass River in Tuscola County, Michigan. It was built in 2015, so it is 10 years old, younger 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 14,550 vehicles a day, roughly 2% of them trucks, projected to reach 16,900 by 2033. The structure is 310 ft (94.6 m) long and 53 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesM-15
CrossesCass River
LocationIn Vassar
RouteState Highway 15
CountyTuscola County
StateMichigan
Coordinates43.3709, -83.58076
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.
Superstructure9 ExcellentNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.4 US tons
Inventory rating38.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadGreater than HL 93
Structure length310 ft (94.6 m)
Longest span81 ft (24.7 m)
Deck width53 ft (16.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,550 (2013)
Projected traffic16,900 by 2033
Trucks2%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-15 over Cass River built?

It was built in 2015, making it 10 years old in 2025.

What condition is M-15 over Cass 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 November 2023.

How much traffic does M-15 over Cass River carry?

About 14,550 vehicles per day (2013 count), of which roughly 2% are trucks.

How long is M-15 over Cass River?

The structure is 310 ft (94.6 m) long with a longest span of 81 ft (24.7 m) and a deck 53 ft wide.

Who owns M-15 over Cass River?

It is owned by the State Highway Agency.