County profile · official public datasets

Santa Cruz County, CA

192 public highway bridges tracked in the FHWA National Bridge Inventory: 40.1% rated Good, 42.2% Fair, 17.7% Poor.

192
Public bridges: 40.1%
Good condition: 17.7%
Poor condition

The verdict

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

Santa Cruz County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

57th
of 58 on Poor share: 17.7%
Poor-condition share: 192
public highway bridges: 1963
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 Cruz County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Santa Cruz County ranks #57 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.7%). Santa Cruz County, California contains 192 public highway bridges. Roughly 40.1% are rated “Good,” 42.2% “Fair,” and 17.7% “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

192

Public highway bridges in Santa Cruz County

Good condition

40.1%

77 of 192 rated 7-9

Fair condition

42.2%

81 of 192 rated 5-6

Poor condition

17.7%

34 of 192 rated 4 or below

In-state Poor-share rank

#57 of 58

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

Condition distribution

Share of 192 NBI-tracked bridges by lowest applicable component rating.

Good

40.1% (77)

Fair

42.2% (81)

Poor

17.7% (34)

Santa Cruz County's Poor-condition bridges carry 182,725 vehicle crossings a day

That is 6.5% of the county's reported daily bridge traffic on 17.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,374 crossings a day against 21,261 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 192 of 192 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

74.5% of Santa Cruz County's bridges have passed the 50-year mark

143 of the 192 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 40.1% 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 16.4% of the county's Poor-condition bridge traffic

STATE ROUTE 1 NB over STATE ROUTE 17, built 1958, carries 30,000 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 34-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 182,725 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

3
1920s

16
1930s

23
1940s

23
1950s

30
1960s

37
1970s

13
1980s

8
1990s

11
2000s

17
2010s

11

What this shows Construction peaked in the 1960s, when 37 of the county's bridges still in the inventory were built, which is 19.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1963, 7 years older than the California average of 1970.

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

The 5 California counties nearest Santa Cruz County in number of bridges, with their condition splits. Its 17.7% Poor share is the 6th-lowest of these 6. Its average build year of 1963 against a peer-group mean of 1969 is 6 years older.

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

Bridge inventory size and condition shares for Santa Cruz County and the 5 California counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Colusa County	211	40.8%	52.1%	7.1%	1968
Marin County	207	43.5%	46.9%	9.7%	1958
Trinity County	194	56.2%	39.7%	4.1%	1977
El Dorado County	192	46.9%	46.9%	6.3%	1975
Santa Cruz County (this page)	192	40.1%	42.2%	17.7%	1963
Kings County	168	40.5%	53.6%	6%	1968

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

Similar inventory size

Nearest county inventories outside CA (192 bridges here).

Barbour County, AL · 192 bridges
Morgan County, CO · 192 bridges
Kent County, DE · 192 bridges
Santa Rosa County, FL · 192 bridges

Similar average build year

Nearest mean year-built outside CA (1963 here).

Worcester County, MA · avg 1963 · 1,014 bridges
Honolulu County, HI · avg 1963 · 682 bridges
Chester County, PA · avg 1963 · 680 bridges
Essex County, NJ · avg 1963 · 505 bridges

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

All 192 Good 77 Fair 81 Poor 34

Poor-condition bridges (34)

Sort:

Santa Cruz County Bridge Snapshot

Condition distribution

Santa Cruz County's Poor-condition bridges carry 182,725 vehicle crossings a day

74.5% of Santa Cruz County's bridges have passed the 50-year mark

One structure carries 16.4% of the county's Poor-condition bridge traffic

How Santa Cruz 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

Poor-condition bridges (34)

GREEN VALLEY RD

GREEN VALLEY RD

STATE ROUTE 1 NB

LOMPICO ROAD

PLEASANT WAY

STATE ROUTE 1 SB

BRIMBLECOM RD

LOMPICO ROAD

HILTON DRIVE

LARKSPUR ST

EAST ZAYANTE RD

CASSERLY RD

EUREKA CANYON RD

SAN ANDREAS RD

STATE ROUTE 129

STATE ROUTE 9

N BIG TREES PRK RD

FOREST HILL DR

BUENA VISTA DRIVE

TWO BAR RD

SWANTON RD

RANCHO RIO AVENUE

STATE ROUTE 236

GLEN ARBOR RD

ISBEL DR

STATE ROUTE 152

ROGGE LANE

MURRAY-EATON ST

MANABE OW ROAD

STOCKTON AVE

GLEN CANYON RD

SCARONI RD

LOMAND ST

PORTER STREET

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