US Bridges

Nfa A402 over South Harpeth Creek

Fair

Williamson County, Tennessee · 5.4 MI SE JCT SR46&SR100 · Structure no. 940A4020001

Built
1960
65 years old
Condition
Fair
inspected June 2023
Type
Tee Beam
Concrete
Length
31 ft
1 main span
Daily traffic
150
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A402 over South Harpeth Creek is a concrete tee beam carrying Nfa A402 over South Harpeth Creek in Williamson County, Tennessee. It was built in 1960, so it is 65 years old, older than the Tennessee average of 47.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 150 vehicles a day, roughly 2% of them trucks, projected to reach 240 by 2041. The structure is 31 ft (9.4 m) long and 22 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesNfa A402
CrossesSouth Harpeth Creek
Location5.4 MI SE JCT SR46&SR100
RouteCounty Highway 402
CountyWilliamson County
StateTennessee
Coordinates35.92204, -87.10104
Functional classRural Local

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating39.7 US tons
Inventory rating26.8 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 10
Structure length31 ft (9.4 m)
Longest span30 ft (9.1 m)
Deck width22 ft (6.6 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic150 (2020)
Projected traffic240 by 2041
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 statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$124,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A402 over South Harpeth Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Nfa A402 over South Harpeth Creek 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 Nfa A402 over South Harpeth Creek carry?

About 150 vehicles per day (2020 count), of which roughly 2% are trucks.

How long is Nfa A402 over South Harpeth Creek?

The structure is 31 ft (9.4 m) long with a longest span of 30 ft (9.1 m) and a deck 22 ft wide.

Who owns Nfa A402 over South Harpeth Creek?

It is owned by the County Highway Agency.