County profile · official public datasets

Loudoun County, VA

442 public highway bridges tracked in the FHWA National Bridge Inventory: 52.7% rated Good, 46.2% Fair, 1.1% Poor.

442
Public bridges: 52.7%
Good condition: 1.1%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Loudoun County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 25%
lowest Poor share in state: 1.1%
Poor-condition share: 442
public highway bridges: 1988
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Loudoun County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Loudoun County ranks #32 of 129 Virginia counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.1%). Loudoun County, Virginia contains 442 public highway bridges. Roughly 52.7% are rated “Good,” 46.2% “Fair,” and 1.1% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

442

Public highway bridges in Loudoun County

Good condition

52.7%

233 of 442 rated 7-9

Fair condition

46.2%

204 of 442 rated 5-6

Poor condition

1.1%

5 of 442 rated 4 or below

In-state Poor-share rank

#32 of 129

Among Virginia counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 442 NBI-tracked bridges by lowest applicable component rating.

Good

52.7% (233)

Fair

46.2% (204)

Poor

1.1% (5)

Loudoun County's Poor-condition bridges carry 12,503 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 1.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,501 crossings a day against 7,721 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 442 of 442 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

24.9% of Loudoun County's bridges have passed the 50-year mark

110 of the 442 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 52.7% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 57.3% of the county's Poor-condition bridge traffic

JOHN S. MOSBY HWY. over GOOSE CREEK, built 1954, carries 7,163 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 5-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 12,503 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

3
1900s

1
1910s

4
1920s

4
1930s

20
1940s

6
1950s

13
1960s

30
1970s

44
1980s

33
1990s

119
2000s

104
2010s

56
2020s

5

What this shows Construction peaked in the 1990s, when 119 of the county's bridges still in the inventory were built, which is 26.9% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1988, 14 years newer than the Virginia average of 1974.

How Loudoun County compares with Virginia's closest counties by inventory size

The 5 Virginia counties nearest Loudoun County in number of bridges, with their condition splits. Its 1.1% Poor share is the 1st-lowest of these 6. Its average build year of 1988 against a peer-group mean of 1978 is 10 years newer.

Showing the 5 closest of 128 Virginia counties eligible for comparison.

Bridge inventory size and condition shares for Loudoun County and the 5 Virginia counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Loudoun County (this page)	442	52.7%	46.2%	1.1%	1988
Augusta County	357	34.7%	62.5%	2.8%	1969
Henrico County	352	15.6%	80.1%	4.3%	1978
Chesterfield County	322	20.8%	76.7%	2.5%	1984
Prince William County	303	54.5%	44.2%	1.3%	1989
Rockingham County	288	53.1%	43.8%	3.1%	1972

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Loudoun County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Loudoun County, both outside Virginia so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside VA (442 bridges here).

Craighead County, AR · 442 bridges
Erie County, PA · 442 bridges
Imperial County, CA · 444 bridges
Licking County, OH · 439 bridges

Similar average build year

Nearest mean year-built outside VA (1988 here).

Travis County, TX · avg 1988 · 1,544 bridges
Grant County, OK · avg 1988 · 476 bridges
Vernon County, MO · avg 1988 · 401 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 442 Good 233 Fair 204 Poor 5

Fair-condition bridges (204)

Sort:

Loudoun County Bridge Snapshot

Condition distribution

Loudoun County's Poor-condition bridges carry 12,503 vehicle crossings a day

24.9% of Loudoun County's bridges have passed the 50-year mark

One structure carries 57.3% of the county's Poor-condition bridge traffic

How Loudoun County compares with Virginia's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (204)

SNICKERSVILLE RD.

AIRMONT ROAD

YELLOW SCHOOLHOUSE

ELKLICK ROAD

CASCADES PARKWAY

ASHBURN ROAD

EVERGREEN MILLS RD

SAINT CLAIR LANE

CLARKES GAP RD

DRY MILL ROAD

D. GREENWAY RAMP I

620 BRADDOCK RD.

RAMP A OF ROUTE 28

MILLTOWN ROAD

EDGEWATER STREET

WILLISVILLE ROAD

UNISON ROAD

JAMES MADISON HIWY

SASSAFRAS ROAD

SAINT LOUIS ROAD

PLANTING FIELD DR

HARRY BYRD HIGHWAY

CHARLESTOWN PIKE

Loudoun Co. Pkwy.

HARRISON STREET

OLD EASTBOUND EXIT

MARKET ST.E.(7EBL)

OLD WHEATLAND ROAD

JAMES MONROE HWY

EVERGREEN MILLS RD

ALGONKIAN PARKWAY

OLD OX ROAD

ASHBURN VILL. SB

ASHBURN VILL. NB

BATTLEFIELD PKWY.

Rte. 28 NB

RAMP H OF D.GRNWAY

ROUTE 7 BYPASS

EB DULLES GREENWAY

WB DULLES GREENWAY

WAXPOOL ROAD

MILLTOWN ROAD

SULLY RD. (RAMP A)

DTRE-RAMPS A&D

GUM SPRINGS ROAD

SYCOLIN ROAD

DULLES GREENWAY EB

RAMP "Q"

DULLES GREENWAY EB

FOXCROFT ROAD

Related