US Bridges

Gratiot Road over Pine River

Good

St. Clair County, Michigan · Sec. 9 ST Clair Twp. · Structure no. 000000000010048

Built
2015
10 years old
Condition
Good
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
200 ft
2 main spans
Daily traffic
4,765
2022 count
Owner
County
County Highway Agency

About this bridge

Gratiot Road over Pine River is a prestressed concrete stringer/multi-beam or girder carrying Gratiot Road over Pine River in St. Clair 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 4,765 vehicles a day, roughly 8% of them trucks, projected to reach 5,807 by 2042. The structure is 200 ft (61 m) long and 43 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesGratiot Road
CrossesPine River
LocationSec. 9 ST Clair Twp.
RouteCounty Highway 7746
CountySt. Clair County
StateMichigan
Coordinates42.88019, -82.56767
Functional classRural Major Collector

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating71.4 US tons
Inventory rating55 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadGreater than HL 93
Structure length200 ft (61 m)
Longest span102 ft (31.2 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,765 (2022)
Projected traffic5,807 by 2042
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Gratiot Road over Pine River built?

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

What condition is Gratiot Road over Pine 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 September 2023.

How much traffic does Gratiot Road over Pine River carry?

About 4,765 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is Gratiot Road over Pine River?

The structure is 200 ft (61 m) long with a longest span of 102 ft (31.2 m) and a deck 43 ft wide.

Who owns Gratiot Road over Pine River?

It is owned by the County Highway Agency.