US Bridges

Nfa A046 over Rock Spring Branch

Fair

Obion County, Tennessee · 3.7 MI NE JCT SR21&SR184 · Structure no. 660A0460003

Built
1983
42 years old
Condition
Fair
inspected March 2023
Type
Culvert
Concrete Continuous
Length
27 ft
2 main spans
Daily traffic
110
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A046 over Rock Spring Branch is a concrete continuous culvert carrying Nfa A046 over Rock Spring Branch in Obion County, Tennessee. It was built in 1983, so it is 42 years old, younger 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 110 vehicles a day, roughly 5% of them trucks, projected to reach 176 by 2041. The structure is 27 ft (8.2 m) long and 25 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesNfa A046
CrossesRock Spring Branch
Location3.7 MI NE JCT SR21&SR184
RouteCounty Highway 46
CountyObion County
StateTennessee
Coordinates36.39091, -89.13892
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating98.2 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span12 ft (3.7 m)
Deck width25 ft (7.6 m)
Roadway width22 ft (6.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2020)
Projected traffic176 by 2041
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A046 over Rock Spring Branch built?

It was built in 1983, making it 42 years old in 2025.

What condition is Nfa A046 over Rock Spring Branch 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 March 2023.

How much traffic does Nfa A046 over Rock Spring Branch carry?

About 110 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is Nfa A046 over Rock Spring Branch?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m) and a deck 25 ft wide.

Who owns Nfa A046 over Rock Spring Branch?

It is owned by the County Highway Agency.