US Bridges

John Mosby Hwy. over Mill Race

Fair

Loudoun County, Virginia · 00.45FR631/00.01TO612 · Structure no. 000000000011118

Built
1929
96 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Concrete
Length
28 ft
1 main span
Daily traffic
9,058
2022 count
Owner
State
State Highway Agency

About this bridge

John Mosby Hwy. over Mill Race is a concrete tee beam carrying John Mosby Hwy. over Mill Race in Loudoun County, Virginia. It was built in 1929, so it is 96 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 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 9,058 vehicles a day, projected to reach 10,100 by 2045. The structure is 28 ft (8.5 m) long and 26 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesJohn Mosby Hwy.
CrossesMill Race
Location00.45FR631/00.01TO612
RouteU.S. Route 50
CountyLoudoun County
StateVirginia
Coordinates38.9754, -77.64027
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.9 US tons
Inventory rating37 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length28 ft (8.5 m)
Longest span28 ft (8.5 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,058 (2022)
Projected traffic10,100 by 2045
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$150 million
NavigationNo navigation control on waterway

Frequently asked questions

When was John Mosby Hwy. over Mill Race built?

It was built in 1929, making it 96 years old in 2025.

What condition is John Mosby Hwy. over Mill Race 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 April 2023.

How much traffic does John Mosby Hwy. over Mill Race carry?

About 9,058 vehicles per day (2022 count).

How long is John Mosby Hwy. over Mill Race?

The structure is 28 ft (8.5 m) long with a longest span of 28 ft (8.5 m) and a deck 26 ft wide.

Who owns John Mosby Hwy. over Mill Race?

It is owned by the State Highway Agency.