US Bridges

Allghny Spg RD/637 over S Fork Roanoke River

Fair

Montgomery County, Virginia · 01.0 RTE 790;00.01 Rt 687 · Structure no. 000000000012250

Built
1975
50 years old
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
107 ft
3 main spans
Daily traffic
560
2022 count
Owner
State
State Highway Agency

About this bridge

Allghny Spg RD/637 over S Fork Roanoke River is a steel stringer/multi-beam or girder carrying Allghny Spg RD/637 over S Fork Roanoke River in Montgomery County, Virginia. It was built in 1975, so it is 50 years old, younger 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 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 560 vehicles a day, roughly 1% of them trucks, projected to reach 730 by 2042. The structure is 107 ft (32.6 m) long and 36 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

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CarriesAllghny Spg RD/637
CrossesS Fork Roanoke River
Location01.0 RTE 790;00.01 Rt 687
RouteCounty Highway 637
CountyMontgomery County
StateVirginia
Coordinates37.10083, -80.25045
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating91.1 US tons
Inventory rating70 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length107 ft (32.6 m)
Longest span36 ft (11 m)
Deck width36 ft (11 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic560 (2022)
Projected traffic730 by 2042
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Allghny Spg RD/637 over S Fork Roanoke River built?

It was built in 1975, making it 50 years old in 2025.

What condition is Allghny Spg RD/637 over S Fork Roanoke River 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 December 2023.

How much traffic does Allghny Spg RD/637 over S Fork Roanoke River carry?

About 560 vehicles per day (2022 count), of which roughly 1% are trucks.

How long is Allghny Spg RD/637 over S Fork Roanoke River?

The structure is 107 ft (32.6 m) long with a longest span of 36 ft (11 m) and a deck 36 ft wide.

Who owns Allghny Spg RD/637 over S Fork Roanoke River?

It is owned by the State Highway Agency.