US Bridges

Salina Road over Thunder Bay River

Fair

Alpena County, Michigan · 15 MI W of Alpena · Structure no. 000000000000348

Built
1984
41 years old
Condition
Fair
inspected August 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
108 ft
3 main spans
Daily traffic
200
2010 count
Owner
County
County Highway Agency

About this bridge

Salina Road over Thunder Bay River is a prestressed concrete box beam or girders - multiple carrying Salina Road over Thunder Bay River in Alpena County, Michigan. It was built in 1984, so it is 41 years old, younger 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 200 vehicles a day, projected to reach 250 by 2030. The structure is 108 ft (32.9 m) long and 31 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesSalina Road
CrossesThunder Bay River
Location15 MI W of Alpena
RouteCounty Highway 423
CountyAlpena County
StateMichigan
Coordinates45.08267, -83.75751
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.6 US tons
Inventory rating38.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length108 ft (32.9 m)
Longest span36 ft (10.9 m)
Deck width31 ft (9.5 m)
Roadway width31 ft (9.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic200 (2010)
Projected traffic250 by 2030
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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 Salina Road over Thunder Bay River built?

It was built in 1984, making it 41 years old in 2025.

What condition is Salina Road over Thunder Bay 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 August 2024.

How much traffic does Salina Road over Thunder Bay River carry?

About 200 vehicles per day (2010 count).

How long is Salina Road over Thunder Bay River?

The structure is 108 ft (32.9 m) long with a longest span of 36 ft (10.9 m) and a deck 31 ft wide.

Who owns Salina Road over Thunder Bay River?

It is owned by the County Highway Agency.