US Bridges

Interstate 81- Nbl over Rte. 691 (johnston Road)

Fair

Smyth County, Virginia · 1.44-RT.16;0.63-RT.11 · Structure no. 000000000017454

Built
1963
62 years old, rebuilt 1982
Condition
Fair
inspected January 2025
Type
Tee Beam
Concrete
Length
112 ft
3 main spans
Daily traffic
17,000
2023 count
Owner
State
State Highway Agency

About this bridge

Interstate 81- Nbl over Rte. 691 (johnston Road) is a concrete tee beam carrying Interstate 81- Nbl over Rte. 691 (johnston Road) in Smyth County, Virginia. It was built in 1963 and reconstructed in 1982, so it is 62 years old, older than the Virginia average of 50.7 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 17,000 vehicles a day, roughly 20% of them trucks, projected to reach 17,363 by 2045. The structure is 112 ft (34.1 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesInterstate 81- Nbl
CrossesRte. 691 (johnston Road)
Location1.44-RT.16;0.63-RT.11
RouteInterstate 81
CountySmyth County
StateVirginia
Coordinates36.84303, -81.4912
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating51 US tons
Inventory rating39 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length112 ft (34.1 m)
Longest span40 ft (12.2 m)
Deck width44 ft (13.4 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,000 (2023)
Projected traffic17,363 by 2045
Trucks20%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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$137.8 million (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Interstate 81- Nbl over Rte. 691 (johnston Road) built?

It was built in 1963, making it 62 years old in 2025. It was reconstructed in 1982.

What condition is Interstate 81- Nbl over Rte. 691 (johnston Road) 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 January 2025.

How much traffic does Interstate 81- Nbl over Rte. 691 (johnston Road) carry?

About 17,000 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is Interstate 81- Nbl over Rte. 691 (johnston Road)?

The structure is 112 ft (34.1 m) long with a longest span of 40 ft (12.2 m) and a deck 44 ft wide.

Who owns Interstate 81- Nbl over Rte. 691 (johnston Road)?

It is owned by the State Highway Agency.