US Bridges

Mackinaw RD over Pinconning River

Fair

Bay County, Michigan · 0.2 MI S of Pinconning RD · Structure no. 000000000000708

Built
1925
100 years old
Condition
Fair
inspected April 2024
Type
Slab
Concrete
Length
22 ft
1 main span
Daily traffic
676
2000 count
Owner
County
County Highway Agency

About this bridge

Mackinaw RD over Pinconning River is a concrete slab carrying Mackinaw RD over Pinconning River in Bay County, Michigan. It was built in 1925, so it is 100 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 676 vehicles a day, roughly 10% of them trucks, projected to reach 1,082 by 2020. The structure is 22 ft (6.7 m) long and 28 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesMackinaw RD
CrossesPinconning River
Location0.2 MI S of Pinconning RD
RouteCounty Highway 0
CountyBay County
StateMichigan
Coordinates43.85114, -83.98627
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating27.3 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length22 ft (6.7 m)
Longest span20 ft (6.1 m)
Deck width28 ft (8.6 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic676 (2000)
Projected traffic1,082 by 2020
Trucks10%
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 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 Mackinaw RD over Pinconning River built?

It was built in 1925, making it 100 years old in 2025.

What condition is Mackinaw RD over Pinconning 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 April 2024.

How much traffic does Mackinaw RD over Pinconning River carry?

About 676 vehicles per day (2000 count), of which roughly 10% are trucks.

How long is Mackinaw RD over Pinconning River?

The structure is 22 ft (6.7 m) long with a longest span of 20 ft (6.1 m) and a deck 28 ft wide.

Who owns Mackinaw RD over Pinconning River?

It is owned by the County Highway Agency.