US Bridges

Nfa A491 over Granny Lewis Creek

Fair

Unicoi County, Tennessee · 1.6 M NE JCT SR36&SR81 · Structure no. 86SR0360007

Built
1951
74 years old
Condition
Fair
inspected July 2024
Type
Tee Beam
Concrete
Length
86 ft
3 main spans
Daily traffic
1,430
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A491 over Granny Lewis Creek is a concrete tee beam carrying Nfa A491 over Granny Lewis Creek in Unicoi County, Tennessee. It was built in 1951, so it is 74 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 5 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 1,430 vehicles a day, roughly 13% of them trucks, projected to reach 2,288 by 2042. The structure is 86 ft (26.2 m) long and 29 ft wide. If it were closed, the detour would be 73.9 mi (119 km).

Location

Open in Google Maps
CarriesNfa A491
CrossesGranny Lewis Creek
Location1.6 M NE JCT SR36&SR81
RouteCounty Highway 491
CountyUnicoi County
StateTennessee
Coordinates36.0874, -82.4858
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating33.2 US tons
Inventory rating25.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length86 ft (26.2 m)
Longest span29 ft (8.7 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,430 (2020)
Projected traffic2,288 by 2042
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed73.9 mi (119 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$163,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A491 over Granny Lewis Creek built?

It was built in 1951, making it 74 years old in 2025.

What condition is Nfa A491 over Granny Lewis 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 July 2024.

How much traffic does Nfa A491 over Granny Lewis Creek carry?

About 1,430 vehicles per day (2020 count), of which roughly 13% are trucks.

How long is Nfa A491 over Granny Lewis Creek?

The structure is 86 ft (26.2 m) long with a longest span of 29 ft (8.7 m) and a deck 29 ft wide.

Who owns Nfa A491 over Granny Lewis Creek?

It is owned by the County Highway Agency.