US Bridges

Gratiot Road over Rattle Run Creek

Good

St. Clair County, Michigan · Sec 18 ST Clair Twp · Structure no. 000000000010047

Built
2017
8 years old
Condition
Good
inspected October 2023
Type
Culvert
Concrete
Length
35 ft
1 main span
Daily traffic
4,250
2017 count
Owner
County
County Highway Agency

About this bridge

Gratiot Road over Rattle Run Creek is a concrete culvert carrying Gratiot Road over Rattle Run Creek in St. Clair County, Michigan. It was built in 2017, so it is 8 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 4,250 vehicles a day, roughly 9% of them trucks, projected to reach 6,315 by 2037. The structure is 35 ft (10.8 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesGratiot Road
CrossesRattle Run Creek
LocationSec 18 ST Clair Twp
RouteCounty Highway 7746
CountySt. Clair County
StateMichigan
Coordinates42.86524, -82.60219
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert8 Very GoodNo problems noted.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating39.2 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadGreater than HL 93
Structure length35 ft (10.8 m)
Longest span33 ft (10.2 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,250 (2017)
Projected traffic6,315 by 2037
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Rattle Run Creek built?

It was built in 2017, making it 8 years old in 2025.

What condition is Gratiot Road over Rattle Run Creek 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 October 2023.

How much traffic does Gratiot Road over Rattle Run Creek carry?

About 4,250 vehicles per day (2017 count), of which roughly 9% are trucks.

How long is Gratiot Road over Rattle Run Creek?

The structure is 35 ft (10.8 m) long with a longest span of 33 ft (10.2 m).

Who owns Gratiot Road over Rattle Run Creek?

It is owned by the County Highway Agency.