US Bridges

M-46 over I-75

Good

Saginaw County, Michigan · @ M-46 · Structure no. 000000000009161

Built
2021
4 years old
Condition
Good
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
202 ft
2 main spans
Daily traffic
16,800
2020 count
Owner
State
State Highway Agency

About this bridge

M-46 over I-75 is a prestressed concrete stringer/multi-beam or girder carrying M-46 over I-75 in Saginaw County, Michigan. It was built in 2021, so it is 4 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 16,800 vehicles a day, roughly 4% of them trucks, projected to reach 18,550 by 2040. The structure is 202 ft (61.7 m) long and 65 ft wide.

Location

Open in Google Maps
CarriesM-46
CrossesI-75
Location@ M-46
RouteState Highway 46
CountySaginaw County
StateMichigan
Coordinates43.41468, -83.8908
Functional classUrban Other Principal Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure9 ExcellentNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation9: Superior to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating69.7 US tons
Inventory rating41.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadGreater than HL 93
Structure length202 ft (61.7 m)
Longest span101 ft (30.8 m)
Deck width65 ft (19.9 m)
Roadway width56 ft (17.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,800 (2020)
Projected traffic18,550 by 2040
Trucks4%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was M-46 over I-75 built?

It was built in 2021, making it 4 years old in 2025.

What condition is M-46 over I-75 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 September 2023.

How much traffic does M-46 over I-75 carry?

About 16,800 vehicles per day (2020 count), of which roughly 4% are trucks.

How long is M-46 over I-75?

The structure is 202 ft (61.7 m) long with a longest span of 101 ft (30.8 m) and a deck 65 ft wide.

Who owns M-46 over I-75?

It is owned by the State Highway Agency.