US Bridges

Gannon Road over Conway-Cohoctah/Sprague

GoodPosted for load

Livingston County, Michigan · Sec 15 Cohoctah Twp · Structure no. 000000000005849

Built
1994
31 years old
Condition
Good
inspected October 2023
Type
Slab
Wood or Timber
Length
32 ft
1 main span
Daily traffic
84
2013 count
Owner
County
County Highway Agency

About this bridge

Gannon Road over Conway-Cohoctah/Sprague is a wood or timber slab carrying Gannon Road over Conway-Cohoctah/Sprague in Livingston County, Michigan. It was built in 1994, so it is 31 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. Its operating status is: posted for load restriction.

It carries about 84 vehicles a day, projected to reach 90 by 2043. The structure is 32 ft (9.7 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesGannon Road
CrossesConway-Cohoctah/Sprague
LocationSec 15 Cohoctah Twp
RouteCounty Highway 0
CountyLivingston County
StateMichigan
Coordinates42.74105, -83.972
Functional classRural Local

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating10 US tons
Inventory rating7.8 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length32 ft (9.7 m)
Longest span30 ft (9.1 m)
Deck width32 ft (9.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic84 (2013)
Projected traffic90 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Gannon Road over Conway-Cohoctah/Sprague built?

It was built in 1994, making it 31 years old in 2025.

What condition is Gannon Road over Conway-Cohoctah/Sprague 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 Gannon Road over Conway-Cohoctah/Sprague carry?

About 84 vehicles per day (2013 count).

How long is Gannon Road over Conway-Cohoctah/Sprague?

The structure is 32 ft (9.7 m) long with a longest span of 30 ft (9.1 m) and a deck 32 ft wide.

Who owns Gannon Road over Conway-Cohoctah/Sprague?

It is owned by the County Highway Agency.