US Bridges

I26 over Overflow

Fair

Unicoi County, Tennessee · 2.4 Mi. S.W. of · Structure no. 86I00260037

Built
1977
48 years old
Condition
Fair
inspected November 2024
Type
Culvert
Concrete Continuous
Length
50 ft
3 main spans
Daily traffic
8,283
2021 count
Owner
State
State Highway Agency

About this bridge

I26 over Overflow is a concrete continuous culvert carrying I26 over Overflow in Unicoi County, Tennessee. It was built in 1977, so it is 48 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 8,283 vehicles a day, roughly 6% of them trucks, projected to reach 18,976 by 2040. The structure is 50 ft (15.1 m) long and 1,690 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesI26
CrossesOverflow
Location2.4 Mi. S.W. of
RouteInterstate 26
CountyUnicoi County
StateTennessee
Coordinates36.12167, -82.44833
Functional classUrban Principal Arterial - Interstate

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 protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 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
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating98.2 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20 + Mod
Structure length50 ft (15.1 m)
Longest span16 ft (4.9 m)
Deck width1,690 ft (515 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,283 (2021)
Projected traffic18,976 by 2040
Trucks6%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$851,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I26 over Overflow built?

It was built in 1977, making it 48 years old in 2025.

What condition is I26 over Overflow 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 November 2024.

How much traffic does I26 over Overflow carry?

About 8,283 vehicles per day (2021 count), of which roughly 6% are trucks.

How long is I26 over Overflow?

The structure is 50 ft (15.1 m) long with a longest span of 16 ft (4.9 m) and a deck 1,690 ft wide.

Who owns I26 over Overflow?

It is owned by the State Highway Agency.