US Bridges

Nfa A506 over South Harpeth River

Good

Cheatham County, Tennessee · 1.2 M. S. I40. · Structure no. 110A5060001

Built
2024
1 years old
Condition
Good
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
68 ft
1 main span
Daily traffic
50
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A506 over South Harpeth River is a prestressed concrete stringer/multi-beam or girder carrying Nfa A506 over South Harpeth River in Cheatham County, Tennessee. It was built in 2024, so it is 1 years old, younger than the Tennessee average of 47.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 50 vehicles a day, roughly 2% of them trucks, projected to reach 80 by 2042. The structure is 68 ft (20.7 m) long and 26 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesNfa A506
CrossesSouth Harpeth River
Location1.2 M. S. I40.
RouteCounty Highway 506
CountyCheatham County
StateTennessee
Coordinates36.06559, -87.0591
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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length68 ft (20.7 m)
Longest span62 ft (18.9 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2020)
Projected traffic80 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$719,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A506 over South Harpeth River built?

It was built in 2024, making it 1 years old in 2025.

What condition is Nfa A506 over South Harpeth 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 2024.

How much traffic does Nfa A506 over South Harpeth River carry?

About 50 vehicles per day (2020 count), of which roughly 2% are trucks.

How long is Nfa A506 over South Harpeth River?

The structure is 68 ft (20.7 m) long with a longest span of 62 ft (18.9 m) and a deck 26 ft wide.

Who owns Nfa A506 over South Harpeth River?

It is owned by the County Highway Agency.