US Bridges

Nfa A408 over Cosby Creek

PoorPosted for load

Cocke County, Tennessee · N of SR32-SE of Cosby · Structure no. 150A4080001

Built
1983
42 years old
Condition
Poor
inspected September 2024
Type
Slab
Concrete Continuous
Length
32 ft
2 main spans
Daily traffic
150
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A408 over Cosby Creek is a concrete continuous slab carrying Nfa A408 over Cosby Creek in Cocke 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 150 vehicles a day, roughly 2% of them trucks, projected to reach 240 by 2042. The structure is 32 ft (9.7 m) long and 30 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesNfa A408
CrossesCosby Creek
LocationN of SR32-SE of Cosby
RouteCounty Highway 408
CountyCocke County
StateTennessee
Coordinates35.78792, -83.2276
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating38.6 US tons
Inventory rating22.8 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length32 ft (9.7 m)
Longest span15 ft (4.7 m)
Deck width30 ft (9 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic150 (2020)
Projected traffic240 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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$43,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A408 over Cosby Creek built?

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

What condition is Nfa A408 over Cosby Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does Nfa A408 over Cosby Creek carry?

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

How long is Nfa A408 over Cosby Creek?

The structure is 32 ft (9.7 m) long with a longest span of 15 ft (4.7 m) and a deck 30 ft wide.

Who owns Nfa A408 over Cosby Creek?

It is owned by the County Highway Agency.