US Bridges

M-46 over Saginaw River

Fair

Saginaw County, Michigan · In Saginaw · Structure no. 000000000009096

Built
1957
68 years old, rebuilt 1997
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
630 ft
9 main spans
Daily traffic
17,266
2007 count
Owner
State
State Highway Agency

About this bridge

M-46 over Saginaw River is a prestressed concrete stringer/multi-beam or girder carrying M-46 over Saginaw River in Saginaw County, Michigan. It was built in 1957 and reconstructed in 1997, so it is 68 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 6 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 17,266 vehicles a day, roughly 7% of them trucks, projected to reach 16,638 by 2018. The structure is 630 ft (192 m) long and 69 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesM-46
CrossesSaginaw River
LocationIn Saginaw
RouteState Highway 46
CountySaginaw County
StateMichigan
Coordinates43.41036, -83.96434
Functional classUrban Other Principal 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating70.3 US tons
Inventory rating41.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans9
Design loadHS 20
Structure length630 ft (192 m)
Longest span71 ft (21.6 m)
Deck width69 ft (21 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,266 (2007)
Projected traffic16,638 by 2018
Trucks7%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was M-46 over Saginaw River built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 1997.

What condition is M-46 over Saginaw 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-46 over Saginaw River carry?

About 17,266 vehicles per day (2007 count), of which roughly 7% are trucks.

How long is M-46 over Saginaw River?

The structure is 630 ft (192 m) long with a longest span of 71 ft (21.6 m) and a deck 69 ft wide.

Who owns M-46 over Saginaw River?

It is owned by the State Highway Agency.