US Bridges

Interstate 81 Sbl over Mulberry Lane (rt 686)

Good

Smyth County, Virginia · 3.3 -Exit 54;0.6 -Exit 50 · Structure no. 000000000030970

Built
2020
5 years old
Condition
Good
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
163 ft
1 main span
Daily traffic
15,284
2022 count
Owner
State
State Highway Agency

About this bridge

Interstate 81 Sbl over Mulberry Lane (rt 686) is a steel stringer/multi-beam or girder carrying Interstate 81 Sbl over Mulberry Lane (rt 686) in Smyth County, Virginia. It was built in 2020, so it is 5 years old, younger than the Virginia average of 50.7 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 15,284 vehicles a day, roughly 1% of them trucks, projected to reach 17,042 by 2042. The structure is 163 ft (49.7 m) long and 46 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesInterstate 81 Sbl
CrossesMulberry Lane (rt 686)
Location3.3 -Exit 54;0.6 -Exit 50
RouteInterstate 81
CountySmyth County
StateVirginia
Coordinates36.86476, -81.42308
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating79 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length163 ft (49.7 m)
Longest span162 ft (49.3 m)
Deck width46 ft (13.9 m)
Roadway width42 ft (12.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,284 (2022)
Projected traffic17,042 by 2042
Trucks1%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed0.6 mi (1 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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Interstate 81 Sbl over Mulberry Lane (rt 686) built?

It was built in 2020, making it 5 years old in 2025.

What condition is Interstate 81 Sbl over Mulberry Lane (rt 686) in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2024.

How much traffic does Interstate 81 Sbl over Mulberry Lane (rt 686) carry?

About 15,284 vehicles per day (2022 count), of which roughly 1% are trucks.

How long is Interstate 81 Sbl over Mulberry Lane (rt 686)?

The structure is 163 ft (49.7 m) long with a longest span of 162 ft (49.3 m) and a deck 46 ft wide.

Who owns Interstate 81 Sbl over Mulberry Lane (rt 686)?

It is owned by the State Highway Agency.