County profile · official public datasets

Alameda County, CA

658 public highway bridges tracked in the FHWA National Bridge Inventory: 35.3% rated Good, 55.2% Fair, 9.6% Poor.

658
Public bridges: 35.3%
Good condition: 9.6%
Poor condition

The verdict

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

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

43rd
of 58 on Poor share: 9.6%
Poor-condition share: 658
public highway bridges: 1973
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.

Alameda County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Alameda County ranks #43 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.6%). Alameda County, California contains 658 public highway bridges. Roughly 35.3% are rated “Good,” 55.2% “Fair,” and 9.6% “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

658

Public highway bridges in Alameda County

Good condition

35.3%

232 of 658 rated 7-9

Fair condition

55.2%

363 of 658 rated 5-6

Poor condition

9.6%

63 of 658 rated 4 or below

In-state Poor-share rank

#43 of 58

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

Condition distribution

Share of 658 NBI-tracked bridges by lowest applicable component rating.

Good

35.3% (232)

Fair

55.2% (363)

Poor

9.6% (63)

Alameda County's Poor-condition bridges carry 3,141,396 vehicle crossings a day

That is 8.5% of the county's reported daily bridge traffic on 9.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 49,863 crossings a day against 61,900 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 658 of 658 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

61.9% of Alameda County's bridges have passed the 50-year mark

407 of the 658 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 35.3% 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 7.2% of the county's Poor-condition bridge traffic

INTERSTATE 880 over CRANDALL CREEK, built 1958, carries 225,000 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 63-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,141,396 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

5
1910s

3
1920s

13
1930s

22
1940s

17
1950s

62
1960s

183
1970s

113
1980s

87
1990s

76
2000s

35
2010s

36
2020s

6

What this shows Construction peaked in the 1960s, when 183 of the county's bridges still in the inventory were built, which is 27.8% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the California average (1970).

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

The 5 California counties nearest Alameda County in number of bridges, with their condition splits. Its 9.6% Poor share is the 5th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1969 is in line with the group.

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

Bridge inventory size and condition shares for Alameda County and the 5 California counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kern County	668	50.1%	43.3%	6.6%	1972
Alameda County (this page)	658	35.3%	55.2%	9.6%	1973
San Joaquin County	644	33.7%	57.1%	9.2%	1968
Contra Costa County	618	42.6%	46.9%	10.5%	1977
Sonoma County	609	24.1%	69%	6.9%	1967
Tulare County	589	42.4%	54.2%	3.4%	1959

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

Similar inventory size

Nearest county inventories outside CA (658 bridges here).

Sumner County, KS · 659 bridges
Salt Lake County, UT · 659 bridges
Bell County, TX · 660 bridges
Lancaster County, NE · 661 bridges

Similar average build year

Nearest mean year-built outside CA (1973 here).

Jefferson County, AL · avg 1973 · 1,068 bridges
Erie County, NY · avg 1973 · 906 bridges
Davidson County, TN · avg 1973 · 832 bridges
Lancaster County, PA · avg 1973 · 801 bridges

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

All 658 Good 232 Fair 363 Poor 63

All bridges (658)

Sort:

Alameda County Bridge Snapshot

Condition distribution

Alameda County's Poor-condition bridges carry 3,141,396 vehicle crossings a day

61.9% of Alameda County's bridges have passed the 50-year mark

One structure carries 7.2% of the county's Poor-condition bridge traffic

How Alameda 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

All bridges (658)

INTERSTATE 580 EB

FRUITVALE AVE

ROUTE 580

ROUTE 580

STATE ROUTE 13 NB

INTERSTATE 880

INTERSTATE 580

PARK ST

HESPERIAN BLVD

INTERSTATE 580 SB

INTERSTATE 680 NB

INTERSTATE 680

I580-ISABEL AVE

INTERSTATE 580

INTERSTATE 580

INTERSTATE 580 EB

INTERSTATE 80 EB

STATE ROUTE 112

HEGENBERGER RD WB

98TH AVE

16TH AVENUE

INTERSTATE 580 EB

INTERSTATE 580 WB

INTERSTATE 580

INTERSTATE 880

N880-WASHINGTON AV

PASEO GRANDE RD

N880-E238 CONNECTR

HACIENDA AVE

INTERSTATE 580 EB

INTERSTATE 580 WB

INTERSTATE 580 WB

INTERSTATE 580 EB

INTERSTATE 580 WB

INTERSTATE 880

S238-E580 CONNECTR

INTERSTATE 580

INTERSTATE 580

SAN RAMON ROAD

STATE ROUTE 238 SB

I 580 EB

STATE ROUTE 238

STATE ROUTE 238 SB

STATE ROUTE 238 NB

INTERSTATE 580

INTERSTATE 580

INTERSTATE 580

GROVE-EB 580 ONRMP

INTERSTATE 580 EB

INTERSTATE 580 WB

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