US Bridges

Gratiot Road over Unnamed Creek

Good

St. Clair County, Michigan · Sec. 24 Columbus Twp. · Structure no. 000000000010045

Built
2021
4 years old
Condition
Good
inspected August 2023
Type
Culvert
Concrete
Length
20 ft
1 main span
Daily traffic
4,250
1994 count
Owner
County
County Highway Agency

About this bridge

Gratiot Road over Unnamed Creek is a concrete culvert carrying Gratiot Road over Unnamed Creek in St. Clair 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 4,250 vehicles a day, roughly 7% of them trucks, projected to reach 4,600 by 2014. The structure is 20 ft (6.1 m) long. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesGratiot Road
CrossesUnnamed Creek
LocationSec. 24 Columbus Twp.
RouteCounty Highway 7746
CountySt. Clair County
StateMichigan
Coordinates42.85635, -82.62221
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 protection7 GoodSome minor problems.
Culvert8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy7: Better than present minimum 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 length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,250 (1994)
Projected traffic4,600 by 2014
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$41,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Gratiot Road over Unnamed Creek built?

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

What condition is Gratiot Road over Unnamed 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 August 2023.

How much traffic does Gratiot Road over Unnamed Creek carry?

About 4,250 vehicles per day (1994 count), of which roughly 7% are trucks.

How long is Gratiot Road over Unnamed Creek?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m).

Who owns Gratiot Road over Unnamed Creek?

It is owned by the County Highway Agency.