County profile · official public datasets

Stanislaus County, CA

386 public highway bridges tracked in the FHWA National Bridge Inventory: 30.8% rated Good, 55.7% Fair, 13.5% Poor.

386
Public bridges: 30.8%
Good condition: 13.5%
Poor condition

The verdict

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

Stanislaus 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.

54th
of 58 on Poor share: 13.5%
Poor-condition share: 386
public highway bridges: 1956
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.

Stanislaus County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Stanislaus County ranks #54 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 13.5%). Stanislaus County, California contains 386 public highway bridges. Roughly 30.8% are rated “Good,” 55.7% “Fair,” and 13.5% “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

386

Public highway bridges in Stanislaus County

Good condition

30.8%

119 of 386 rated 7-9

Fair condition

55.7%

215 of 386 rated 5-6

Poor condition

13.5%

52 of 386 rated 4 or below

In-state Poor-share rank

#54 of 58

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

Condition distribution

Share of 386 NBI-tracked bridges by lowest applicable component rating.

Good

30.8% (119)

Fair

55.7% (215)

Poor

13.5% (52)

Stanislaus County's Poor-condition bridges carry 530,953 vehicle crossings a day

That is 14% of the county's reported daily bridge traffic on 13.5% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 10,211 crossings a day against 12,914 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 386 of 386 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

80.1% of Stanislaus County's bridges have passed the 50-year mark

309 of the 386 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 30.8% 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 13.5% of the county's Poor-condition bridge traffic

BRIGGSMORE ROAD over UP RR & BRINK AVENUE, built 1976, carries 71,797 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 52-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 530,953 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

27
1920s

82
1930s

25
1940s

22
1950s

24
1960s

103
1970s

35
1980s

17
1990s

17
2000s

13
2010s

9
2020s

11

What this shows Construction peaked in the 1960s, when 103 of the county's bridges still in the inventory were built, which is 26.7% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1956, 14 years older than the California average of 1970.

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

The 5 California counties nearest Stanislaus County in number of bridges, with their condition splits. Its 13.5% Poor share is the 6th-lowest of these 6. Its average build year of 1956 against a peer-group mean of 1970 is 14 years older.

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

Bridge inventory size and condition shares for Stanislaus County and the 5 California counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
San Luis Obispo County	401	47.6%	46.6%	5.7%	1970
Humboldt County	396	38.9%	54.3%	6.8%	1968
Stanislaus County (this page)	386	30.8%	55.7%	13.5%	1956
Monterey County	377	56.8%	35.5%	7.7%	1970
Solano County	373	44.8%	47.5%	7.8%	1975
San Mateo County	361	26%	64%	10%	1967

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

Similar inventory size

Nearest county inventories outside CA (386 bridges here).

Calhoun County, AL · 386 bridges
Gibson County, TN · 386 bridges
Alfalfa County, OK · 387 bridges
Delaware County, PA · 387 bridges

Similar average build year

Nearest mean year-built outside CA (1956 here).

Philadelphia County, PA · avg 1956 · 585 bridges
Cochise County, AZ · avg 1956 · 501 bridges
Hampden County, MA · avg 1956 · 428 bridges
Washington County, MD · avg 1956 · 300 bridges

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

All 386 Good 119 Fair 215 Poor 52

Good-condition bridges (119)

Sort:

Stanislaus County Bridge Snapshot

Condition distribution

Stanislaus County's Poor-condition bridges carry 530,953 vehicle crossings a day

80.1% of Stanislaus County's bridges have passed the 50-year mark

One structure carries 13.5% of the county's Poor-condition bridge traffic

How Stanislaus 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

Good-condition bridges (119)

Bell Road

NO DATA ENTERED

STARK ROAD

FRANK COX ROAD

8TH & 9TH STREET

ELM AVENUE

SONORA ROAD

SALIDA BOULEVARD

ST FRANCIS AVENUE

WARD AVENUE

SYCAMORE AVENUE

DEL PUERTO CYN RD

FRANK RAIN ORV PK

SHEARWATER DRIVE

STATE ROUTE 33

MILTON ROAD

MILTON ROAD

PINE STREET

STATE ROUTE 132

HAMMETT RD

INTERSTATE 5 NB

INTERSTATE 5 NB

G STREET

INTERSTATE 5 NB

PETE MILLER RD

STUHR ROAD

SPERRY ROAD

STATE ROUTE 99 SB

STATE ROUTE 99 NB

STATE ROUTE 99 SB

STATE ROUTE 99 NB

RIVER ROAD

LAKE ROAD

STATE ROUTE 99 SB

STATE ROUTE 99 NB

HATCH ROAD

STUHR ROAD

STATE ROUTE 99 SB

MCHENRY AVENUE

STATE ROUTE 99

INTERSTATE 5 SB

INTERSTATE 5 NB

STATE ROUTE 99

STATE ROUTE 99 SB

STATE ROUTE 99 NB

PIONEER AVENUE

STATE ROUTE 120

LINWOOD AVE

CARPENTER-BRIGSMRE

KEYES ROAD

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