County profile · official public datasets

Fairfax County, VA

751 public highway bridges tracked in the FHWA National Bridge Inventory: 54.7% rated Good, 44.2% Fair, 1.1% Poor.

751
Public bridges
54.7%
Good condition
1.1%
Poor condition

The verdict

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

Fairfax 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 23%
lowest Poor share in state
1.1%
Poor-condition share
751
public highway bridges
1990
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.

Fairfax County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Fairfax County ranks #30 of 129 Virginia counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.1%). Fairfax County, Virginia contains 751 public highway bridges. Roughly 54.7% are rated “Good,” 44.2% “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

751

Public highway bridges in Fairfax County

Good condition

54.7%

411 of 751 rated 7-9

Fair condition

44.2%

332 of 751 rated 5-6

Poor condition

1.1%

8 of 751 rated 4 or below

In-state Poor-share rank

#30 of 129

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

Condition distribution

Share of 751 NBI-tracked bridges by lowest applicable component rating.

Good
54.7% (411)
Fair
44.2% (332)
Poor
1.1% (8)

Fairfax County's Poor-condition bridges carry 107,939 vehicle crossings a day

That is 0.5% 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 13,492 crossings a day against 28,818 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 751 of 751 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

25.3% of Fairfax County's bridges have passed the 50-year mark

190 of the 751 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 54.7% 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 49.1% of the county's Poor-condition bridge traffic

EB G.W.MEM.PKWY over ROUTE I-495, built 1962, carries 53,000 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 107,939 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Fairfax County's bridges were built

751 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1990s, when 146 of the county's bridges still in the inventory were built, which is 19.4% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1990, 16 years newer than the Virginia average of 1974.

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Virginia counties nearest Fairfax 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 1990 against a peer-group mean of 1982 is 8 years newer.

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

Bridge inventory size and condition shares for Fairfax County and the 5 Virginia counties closest to it in inventory size
County Bridges Poor
Fairfax County (this page) 751 1.1%
Loudoun County 442 1.1%
Augusta County 357 2.8%
Henrico County 352 4.3%
Chesterfield County 322 2.5%
Prince William County 303 1.3%

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 Fairfax 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 Fairfax County, both outside Virginia so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside VA (751 bridges here).

Similar average build year

Nearest mean year-built outside VA (1990 here).

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

All 751 Good 411 Fair 332 Poor 8

Good-condition bridges (411)

FAIRFAX CO. PKWY.

Good

Over: FLATLICK BRANCH

00.20FR7155/00.05TO7140, Fairfax, VA

Built 1988 Load: 89.8 t ADT: 52,433

FAIRFAX CO.PKWY.

Good

Over: LONG BRANCH CREEK

01.10FR617/00.20TO611, Fairfax, VA

Built 1997 Load: 89.8 t ADT: 36,629

MONUMENT DR.

Good

Over: DIFFICULT RUN

00.22FR GCP/00.35TO FCA, Fairfax, VA

Built 2004 Load: 89.8 t ADT: 8,681

RAMP LRNW

Good

Over: ACCOTINK CREEK

00.04FR495 / 00.06TO236, Fairfax, VA

Built 2011 Load: 89.8 t ADT: 2,766

MARSHALL LAKE DR.

Good

Over: SOUTH FORK RUN

00.65FR0672/00.02TO0000, Fairfax, VA

Built 2004 Load: 89.8 t ADT: 566

RTE.29 LEE HWY.

Good

Over: LITTLE ROCKY RUN

0.85fr28 0.5to645, Fairfax, VA

Built 2015 Load: 89.8 t ADT: 15,504

Ramp H to Rte 7

Good

Over: Pedestrian Underpass

00.50fr267 00.01to7, Fairfax, VA

Built 2016 Load: 89.8 t ADT: 4,300

CARPERS FARM WAY

Good

Over: COLVIN RUN

00.02FR7/00.04TO6708, Fairfax, VA

Built 2021 Load: 89.8 t ADT: 1,156

ROUTE 28 NB

Good

Over: ROUTE 28 SB RAMP

.04FR28/0.5TO BRADDOCK, Fairfax, VA

Built 2020 Load: 89.8 t ADT: 16,000

Lee Highway

Good

Over: I-495

00.09FR0703/00.36TO0650, Fairfax, VA

Built 2010 Load: 90.4 t ADT: 30,283

POTTERTON DR.

Good

Over: LAKE BARCROFT

00.04FR2276/00.07TO1886, Fairfax, VA

Built 2002 Load: 90.5 t ADT: 2,209

Read our methodology - how this data is sourced, computed, and verified.

Related

Browse all → | Rankings →
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.