US Bridges

Interstate 81 Nbl over M. Fork Holston River

Poor

Smyth County, Virginia · 0.69 FR Wcl - .50 to 762 · Structure no. 000000000017427

Built
1962
63 years old, rebuilt 1985
Condition
Poor
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
238 ft
4 main spans
Daily traffic
16,486
2022 count
Owner
State
State Highway Agency

About this bridge

Interstate 81 Nbl over M. Fork Holston River is a steel stringer/multi-beam or girder carrying Interstate 81 Nbl over M. Fork Holston River in Smyth County, Virginia. It was built in 1962 and reconstructed in 1985, so it is 63 years old, older than the Virginia average of 50.7 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.

It carries about 16,486 vehicles a day, roughly 1% of them trucks, projected to reach 17,260 by 2045. The structure is 238 ft (72.4 m) long and 38 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesInterstate 81 Nbl
CrossesM. Fork Holston River
Location0.69 FR Wcl - .50 to 762
RouteInterstate 81
Coordinates36.78916, -81.6872
Functional classRural Principal Arterial - Interstate

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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64 US tons
Inventory rating49.1 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length238 ft (72.4 m)
Longest span59 ft (18 m)
Deck width38 ft (11.5 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,486 (2022)
Projected traffic17,260 by 2045
Trucks1%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$130.9 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Interstate 81 Nbl over M. Fork Holston River built?

It was built in 1962, making it 63 years old in 2025. It was reconstructed in 1985.

What condition is Interstate 81 Nbl over M. Fork Holston River 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 February 2024.

How much traffic does Interstate 81 Nbl over M. Fork Holston River carry?

About 16,486 vehicles per day (2022 count), of which roughly 1% are trucks.

How long is Interstate 81 Nbl over M. Fork Holston River?

The structure is 238 ft (72.4 m) long with a longest span of 59 ft (18 m) and a deck 38 ft wide.

Who owns Interstate 81 Nbl over M. Fork Holston River?

It is owned by the State Highway Agency.