County profile · official public datasets

Santa Clara County, CA

964 public highway bridges tracked in the FHWA National Bridge Inventory: 38.3% rated Good, 56.1% Fair, 5.6% Poor.

964
Public bridges: 38.3%
Good condition: 5.6%
Poor condition

The verdict

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

Santa Clara County posts a better-than-median Poor-condition share among rated counties in the state across large county bridge inventory.

Top 31%
lowest Poor share in state: 5.6%
Poor-condition share: 964
public highway bridges: 1972
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.

Santa Clara County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Santa Clara County ranks #18 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.6%). Santa Clara County, California contains 964 public highway bridges. Roughly 38.3% are rated “Good,” 56.1% “Fair,” and 5.6% “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

964

Public highway bridges in Santa Clara County

Good condition

38.3%

369 of 964 rated 7-9

Fair condition

56.1%

541 of 964 rated 5-6

Poor condition

5.6%

54 of 964 rated 4 or below

In-state Poor-share rank

#18 of 58

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

Condition distribution

Share of 964 NBI-tracked bridges by lowest applicable component rating.

Good

38.3% (369)

Fair

56.1% (541)

Poor

5.6% (54)

Santa Clara County's Poor-condition bridges carry 1,499,973 vehicle crossings a day

That is 4.8% of the county's reported daily bridge traffic on 5.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 27,777 crossings a day against 34,452 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 964 of 964 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

56.5% of Santa Clara County's bridges have passed the 50-year mark

545 of the 964 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 38.3% 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 11% of the county's Poor-condition bridge traffic

INTERSTATE 880 over NORTH FOURTH STREET, built 1960, carries 165,000 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 54-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,499,973 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

5
1910s

24
1920s

38
1930s

28
1940s

29
1950s

64
1960s

215
1970s

189
1980s

95
1990s

196
2000s

60
2010s

21

What this shows Construction peaked in the 1960s, when 215 of the county's bridges still in the inventory were built, which is 22.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1972) matches the California average (1970).

How Santa Clara County compares with California's closest counties by inventory size

The 5 California counties nearest Santa Clara County in number of bridges, with their condition splits. Its 5.6% Poor share is the 5th-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1974 is in line with the group.

Showing the 5 closest of 57 California counties eligible for comparison.

Bridge inventory size and condition shares for Santa Clara County and the 5 California counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Orange County	1,164	53.2%	43.8%	3%	1978
Riverside County	1,117	56.4%	41.2%	2.4%	1977
Santa Clara County (this page)	964	38.3%	56.1%	5.6%	1972
Fresno County	916	38.9%	57.3%	3.8%	1969
Sacramento County	740	50.9%	45.7%	3.4%	1973
Kern County	668	50.1%	43.3%	6.6%	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 Santa Clara 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 Santa Clara County, both outside California so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside CA (964 bridges here).

Marion County, IN · 958 bridges
Denton County, TX · 991 bridges
Hennepin County, MN · 936 bridges
Jackson County, MO · 930 bridges

Similar average build year

Nearest mean year-built outside CA (1972 here).

Madison County, AL · avg 1972 · 710 bridges
York County, PA · avg 1972 · 569 bridges
Middlesex County, NJ · avg 1972 · 563 bridges
Saunders County, NE · avg 1972 · 506 bridges

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

All 964 Good 369 Fair 541 Poor 54

Fair-condition bridges (541)

Sort:

Santa Clara County Bridge Snapshot

Condition distribution

Santa Clara County's Poor-condition bridges carry 1,499,973 vehicle crossings a day

56.5% of Santa Clara County's bridges have passed the 50-year mark

One structure carries 11% of the county's Poor-condition bridge traffic

How Santa Clara County compares with California'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 (541)

STATE ROUTE 237

ALDERCROFT HTS RD

ALAMITOS ROAD

ALMADEN WAY

BERTRAM ROAD

MERIDIAN ROAD (SB)

ALAMITOS ROAD

PORTLAND AVE

LLAGAS AVE

LLAGAS AVE

SB 85-WB 237 RAMP

VIRGINIA STREET

NEWELL RD

CROY RD

HELLYER AVE

FARRELL AVE

MOFFETT BOULEVARD

FREMONT AVE

MCCLELLAN RD

PRUNERIDGE AVE

ALDERCROFT HTS RD

STEVENS CYN RD

WHITEHURST ROAD

ALUM ROCK FALLS RD

VILLA MARIA ENT RD

STEVENS CYN RD

VIA REAL DRIVE

STATE ROUTE 9

MC KEAN ROAD

SAN FERNANDO ST

POMEROY AVE

ALMADEN EXPWY

REDWOOD RETREAT RD

EL CAMINO REAL

MATADERO RD

FRAZIER LAKE ROAD

PIERCE RD

ALAMITOS ROAD

OLD PAGE MILL ROAD

OLD PAGE MILL ROAD

SB STATE ROUTE 87

NEW AVE

BROKAW RD

VIRGINIA ST

ALAMITOS ROAD

FRAZIER LAKE ROAD

OLD PAGE MILL ROAD

OLD PAGEMILL ROAD

STEVENS CYN RD

N280-S17 CONNECTOR

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