US Bridges

Flat Rock Road over Salmon River

Good

Franklin County, New York · 2.6 MI SW Constable · Structure no. 000000003337450

Built
1995
30 years old
Condition
Good
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
90 ft
1 main span
Daily traffic
799
2017 count
Owner
County
County Highway Agency

About this bridge

Flat Rock Road over Salmon River is a prestressed concrete box beam or girders - multiple carrying Flat Rock Road over Salmon River in Franklin County, New York. It was built in 1995, so it is 30 years old, younger than the New York average of 53 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.

It carries about 799 vehicles a day, roughly 17% of them trucks, projected to reach 1,119 by 2037. The structure is 90 ft (27.4 m) long and 18 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesFlat Rock Road
CrossesSalmon River
Location2.6 MI SW Constable
Coordinates44.91772, -74.3464
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
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating74 US tons
Inventory rating45 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length90 ft (27.4 m)
Longest span85 ft (25.9 m)
Deck width18 ft (5.5 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic799 (2017)
Projected traffic1,119 by 2037
Trucks17%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$577,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Flat Rock Road over Salmon River built?

It was built in 1995, making it 30 years old in 2025.

What condition is Flat Rock Road over Salmon River 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 July 2023.

How much traffic does Flat Rock Road over Salmon River carry?

About 799 vehicles per day (2017 count), of which roughly 17% are trucks.

How long is Flat Rock Road over Salmon River?

The structure is 90 ft (27.4 m) long with a longest span of 85 ft (25.9 m) and a deck 18 ft wide.

Who owns Flat Rock Road over Salmon River?

It is owned by the County Highway Agency.