US Bridges

Blair Road over Maple River

Fair

Gratiot County, Michigan · Sec. 25-26 Washington Twp · Structure no. 000000000003167

Built
1967
58 years old
Condition
Fair
inspected June 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
135 ft
3 main spans
Daily traffic
330
2003 count
Owner
County
County Highway Agency

About this bridge

Blair Road over Maple River is a prestressed concrete box beam or girders - multiple carrying Blair Road over Maple River in Gratiot County, Michigan. It was built in 1967, so it is 58 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 5 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 330 vehicles a day, projected to reach 445 by 2023. The structure is 135 ft (41.1 m) long and 30 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesBlair Road
CrossesMaple River
LocationSec. 25-26 Washington Twp
RouteCounty Highway 2971
CountyGratiot County
StateMichigan
Coordinates43.14491, -84.50357
Functional classRural Major Collector

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating73.4 US tons
Inventory rating44 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20 + Mod
Structure length135 ft (41.1 m)
Longest span44 ft (13.4 m)
Deck width30 ft (9.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic330 (2003)
Projected traffic445 by 2023
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 Blair Road over Maple River built?

It was built in 1967, making it 58 years old in 2025.

What condition is Blair Road over Maple 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 June 2023.

How much traffic does Blair Road over Maple River carry?

About 330 vehicles per day (2003 count).

How long is Blair Road over Maple River?

The structure is 135 ft (41.1 m) long with a longest span of 44 ft (13.4 m) and a deck 30 ft wide.

Who owns Blair Road over Maple River?

It is owned by the County Highway Agency.