County profile · official public datasets

Solano County, CA

373 public highway bridges tracked in the FHWA National Bridge Inventory: 44.8% rated Good, 47.5% Fair, 7.8% Poor.

373
Public bridges
44.8%
Good condition
7.8%
Poor condition

The verdict

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

Solano County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

38th
of 58 on Poor share
7.8%
Poor-condition share
373
public highway bridges
1975
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.

Solano County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Solano County ranks #38 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.8%). Solano County, California contains 373 public highway bridges. Roughly 44.8% are rated “Good,” 47.5% “Fair,” and 7.8% “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

373

Public highway bridges in Solano County

Good condition

44.8%

167 of 373 rated 7-9

Fair condition

47.5%

177 of 373 rated 5-6

Poor condition

7.8%

29 of 373 rated 4 or below

In-state Poor-share rank

#38 of 58

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

Condition distribution

Share of 373 NBI-tracked bridges by lowest applicable component rating.

Good
44.8% (167)
Fair
47.5% (177)
Poor
7.8% (29)

Solano County's Poor-condition bridges carry 1,450,968 vehicle crossings a day

That is 21.7% of the county's reported daily bridge traffic on 7.8% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 50,033 crossings a day against 14,119 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 373 of 373 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

53.9% of Solano County's bridges have passed the 50-year mark

201 of the 373 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 44.8% 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 13.9% of the county's Poor-condition bridge traffic

INTERSTATE 80 over DAN WILSON CREEK, built 1951, carries 202,000 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 29-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,450,968 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Solano County's bridges were built

373 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 91 of the county's bridges still in the inventory were built, which is 24.4% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1975, 5 years newer than the California average of 1970.

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 California counties nearest Solano County in number of bridges, with their condition splits. Its 7.8% Poor share is the 4th-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1966 is 9 years newer.

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

Bridge inventory size and condition shares for Solano County and the 5 California counties closest to it in inventory size
County Bridges Poor
Humboldt County 396 6.8%
Stanislaus County 386 13.5%
Monterey County 377 7.7%
Solano County (this page) 373 7.8%
San Mateo County 361 10%
Mendocino County 357 7.6%

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

Similar inventory size

Nearest county inventories outside CA (373 bridges here).

Similar average build year

Nearest mean year-built outside CA (1975 here).

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

All 373 Good 167 Fair 177 Poor 29

Fair-condition bridges (177)

INTERSTATE 505 NB

Fair

Over: MIDWAY RD

04-SOL-505-R3.06-VAC, Solano, CA

Built 1974 Load: 34.0 t ADT: 16,750

WALNUT ST

Fair

Over: STATE ROUTE 37

04-SOL-037-R7.21-VAL, Solano, CA

Built 1967 Load: 34.3 t ADT: 2,000

INTERSTATE 505 NB

Fair

Over: ALLENDALE RD

04-SOL-505-R5.57, Solano, CA

Built 1974 Load: 34.3 t ADT: 11,400

E80-N113 CONNECTOR

Fair

Over: SOUTH FORK PUTAH CREEK

04-SOL-080-42.37, Solano, CA

Built 1974 Load: 35.3 t ADT: 9,900

PITT SCHOOL ROAD

Fair

Over: INTERSTATE 80 & RAMPS

04-SOL-080-36.90-DXN, Solano, CA

Built 1963 Load: 36.6 t ADT: 470

BROWN ROAD

Fair

Over: ULATIS CREEK

1.5 MI E OF RTE 113, Solano, CA

Built 1963 Load: 36.6 t ADT: 81

LAKE HERMAN ROAD

Fair

Over: INTERSTATE 680

04-SOL-680-R2.82, Solano, CA

Built 1966 Load: 37.3 t ADT: 1,000

S505-E80 CONNECTOR

Fair

Over: INTERSTATE 80 & S505-W80

04-SOL-505-R0.01-VAC, Solano, CA

Built 1963 Load: 37.6 t ADT: 1,100

BECK AVE

Fair

Over: ALONZO DRAIN

S/O BARNHART ROAD, Solano, CA

Built 1985 Load: 37.6 t ADT: 8,980

OAKWOOD AVE

Fair

Over: BLUE ROCK SPRINGS CREEK

0.1 MI S REDWOOD PKWY, Solano, CA

Built 1987 Load: 37.9 t ADT: 7,931

EB TRAVIS BLVD

Fair

Over: INTERSTATE 80 & RAMPS

04-SOL-080-17.92-FRFD, Solano, CA

Built 1963 Load: 38.6 t ADT: 10,978

PADDON ROAD

Fair

Over: PUTAH SOUTH CANAL

0.3 MI N ROBINSON ROAD, Solano, CA

Built 1955 Load: 38.6 t ADT: 241

MERIDIAN RD

Fair

Over: SWEENEY CREEK

1.8 MI N MIDWAY RD, Solano, CA

Built 1972 Load: 38.6 t ADT: 877

LEWIS ROAD

Fair

Over: NEW ALAMO CREEK CHANNEL

0.5 MI SOUTH OF FRY RD, Solano, CA

Built 1966 Load: 39.2 t ADT: 554

E37-E80 CONNECTOR

Fair

Over: INTERSTATE 80

04-SOL-037-R11.65R-VAL, Solano, CA

Built 1975 Load: 40.2 t ADT: 14,500

SALEM ROAD

Fair

Over: OLD ALAMO CREEK

1.0 MI S BROWN RD, Solano, CA

Built 1966 Load: 40.5 t ADT: 44

STATE ROUTE 12

Fair

Over: UNION CREEK

04-SOL-012-8.54, Solano, CA

Built 1957 Load: 41.8 t ADT: 12,200

FOX ROAD

Fair

Over: HORSE CREEK

0.8 MI N OF HAWKINS RD, Solano, CA

Built 1966 Load: 42.4 t ADT: 57

INTERSTATE 80 WB

Fair

Over: ULATIS CREEK

04-SOL-080-R26.61-VAC, Solano, CA

Built 1952 Load: 43.7 t ADT: 70,500

ODAY ROAD

Fair

Over: SWEENEY CREEK

ADJ TO I-80, Solano, CA

Built 1963 Load: 44.1 t ADT: 98

INTERSTATE 80 EB

Fair

Over: MASON STREET

04-SOL-080-R26.46-VAC, Solano, CA

Built 1952 Load: 44.4 t ADT: 80,500

W80-S113 N113-W80

Fair

Over: I-80 & RMPS (@ PM 38.21)

04-SOL-113-21.21-DXN, Solano, CA

Built 1963 Load: 49.6 t ADT: 7,200

TIMM ROAD

Fair

Over: SWEENEY CREEK

1.5 MI W/O I-505, Solano, CA

Built 1981 Load: 52.5 t ADT: 2,512

COUNTRY CLUB DRIVE

Fair

Over: SULFER SPRINGS CREEK

0.1 MI E OF HIDDENBROOKE, Solano, CA

Built 2002 Load: 52.5 t ADT: 300

DIXON AVENUE

Fair

Over: INTERSTATE 80 & RAMPS

04-SOL-080-35.55-DXN, Solano, CA

Built 1963 Load: 54.1 t ADT: 2,617

MIDWAY ROAD

Fair

Over: SWEENY CREEK

0.45 MI E OF I-80, Solano, CA

Built 1970 Load: 59.9 t ADT: 5,000

MIDWAY ROAD

Fair

Over: MC CUNE CREEK

1.3 MI E OF I-80, Solano, CA

Built 1970 Load: 66.1 t ADT: 5,000

Read our methodology - how this data is sourced, computed, and verified.

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.