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.

Compiled by PlainBridges

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.

1920s

3
1930s

14
1940s

3
1950s

15
1960s

116
1970s

65
1980s

121
1990s

146
2000s

110
2010s

110
2020s

48

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.

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	Good	Fair	Poor	Avg. built
Fairfax County (this page)	751	54.7%	44.2%	1.1%	1990
Loudoun County	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

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).

Mecklenburg County, NC · 746 bridges
Wake County, NC · 760 bridges
Sacramento County, CA · 740 bridges
Guilford County, NC · 736 bridges

Similar average build year

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

Maricopa County, AZ · avg 1990 · 2,847 bridges
Tarrant County, TX · avg 1990 · 2,617 bridges
Brazoria County, TX · avg 1990 · 618 bridges

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

All bridges (751)

Sort:

Fairfax County Bridge Snapshot

Condition distribution

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

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

One structure carries 49.1% of the county's Poor-condition bridge traffic

How Fairfax 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

All bridges (751)

RMPS; HN-E & HE-N

ROUTE 28 NB

POLO PLACE

Route 28 NB

FAIRFAX COUNTY PKY

SAMAGA DRIVE

JARRETT VALLEY DR.

LEE CHAPEL ROAD

I-66 CD ROAD

THORNCLIFF LANE

FAIRFAX COUNTY PKY

TELEGRAPH ROAD

BEACH MILL ROAD

MONROE STREET

CEDAR GLEN LANE

I-495 Ramp GNGW

WALNEY RD.

66 WBL

FAIR LAKES CIRCLE

RAMP LEWSH & LSEWH

STRINGFELLOW ROAD

WESTPARK DRIVE

DIAAH & DTR

RAMPS BNEWH &BEWNH

IDYLWOOD ROAD

HERNDON PARKWAY

TRINITY PKWY

HAMPTON ROAD

HOOES ROAD

FAIRFAX CO. PKWY.

SCOTT CROSSING RD.

FAIRFAX CO. PKWY.

FAIRFAX CO. PKWY.

FAIRFAX CO.PKWY.

MONUMENT DR.

RAMP LRNW

MARSHALL LAKE DR.

RTE.29 LEE HWY.

Ramp H to Rte 7

CARPERS FARM WAY

ROUTE 28 NB

Lee Highway

POTTERTON DR.

OLD COLCHESTER RD.

BEACH MILL ROAD

SLEEPY HOLLOW ROAD

CHAINBRIDGE RD NBL

EB G.W.MEM.PKWY

WB G.W.MEM.PKWY.

KING ARTHUR ROAD

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