County profile · official public datasets

Kern County, CA

668 public highway bridges tracked in the FHWA National Bridge Inventory: 50.1% rated Good, 43.3% Fair, 6.6% Poor.

668
Public bridges
50.1%
Good condition
6.6%
Poor condition

The verdict

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

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

Top 47%
lowest Poor share in state
6.6%
Poor-condition share
668
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.

Kern County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Kern County ranks #27 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.6%). Kern County, California contains 668 public highway bridges. Roughly 50.1% are rated “Good,” 43.3% “Fair,” and 6.6% “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

668

Public highway bridges in Kern County

Good condition

50.1%

335 of 668 rated 7-9

Fair condition

43.3%

289 of 668 rated 5-6

Poor condition

6.6%

44 of 668 rated 4 or below

In-state Poor-share rank

#27 of 58

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

Condition distribution

Share of 668 NBI-tracked bridges by lowest applicable component rating.

Good
50.1% (335)
Fair
43.3% (289)
Poor
6.6% (44)

Kern County's Poor-condition bridges carry 468,180 vehicle crossings a day

That is 5.3% of the county's reported daily bridge traffic on 6.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 10,640 crossings a day against 15,153 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 668 of 668 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

67.7% of Kern County's bridges have passed the 50-year mark

452 of the 668 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 50.1% 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 11.3% of the county's Poor-condition bridge traffic

STATE ROUTE 99 over HIGH ST & UP RR, built 1955, carries 53,000 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 44-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 468,180 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Kern County's bridges were built

668 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 200 of the county's bridges still in the inventory were built, which is 29.9% 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).

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

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

The 5 California counties nearest Kern County in number of bridges, with their condition splits. Its 6.6% Poor share is the 2nd-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1972 is in line with the group.

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

Bridge inventory size and condition shares for Kern County and the 5 California counties closest to it in inventory size
County Bridges Poor
Sacramento County 740 3.4%
Kern County (this page) 668 6.6%
Alameda County 658 9.6%
San Joaquin County 644 9.2%
Contra Costa County 618 10.5%
Sonoma County 609 6.9%

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

Similar inventory size

Nearest county inventories outside CA (668 bridges here).

Similar average build year

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

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

Fair-condition bridges (289)

STATE ROUTE 178

Fair

Over: EAST SIDE CANAL

06-KER-178-R2.42-BKD, Kern, CA

Built 1986 Load: 24.3 t ADT: 75,000

STATE ROUTE 155

Fair

Over: TILLIE CREEK OVERFLOW

06-KER-155-R60.88, Kern, CA

Built 1951 Load: 24.3 t ADT: 6,300

STATE ROUTE 155

Fair

Over: RATTLESNAKE CREEK

06-KER-155-64.92, Kern, CA

Built 1951 Load: 24.3 t ADT: 6,600

STATE ROUTE 14 SB

Fair

Over: STATE ROUTE 58

09-KER-014-19.00, Kern, CA

Built 2003 Load: 24.3 t ADT: 4,800

UNION AVENUE

Fair

Over: EAST BRANCH CANAL

0.05MI N/O BELLE TERRACE, Kern, CA

Built 1914 Load: 24.3 t ADT: 29,000

WALKER BASIN RD

Fair

Over: RANCHERIA CREEK

1.17 MI W PIUTE MOUNTN RD, Kern, CA

Built 1971 Load: 24.3 t ADT: 180

OLD RIVER ROAD

Fair

Over: CALIFORNIA AQUEDUCT

0.5 MI NORTH OF RTE 166, Kern, CA

Built 1968 Load: 24.3 t ADT: 2,301

6TH STREET

Fair

Over: SANDY CREEK

SOUTH OF ASH STREET, Kern, CA

Built 1972 Load: 24.3 t ADT: 6,500

OLIVE DRIVE

Fair

Over: CANAL LATERAL 29

EAST OF STATE RD, Kern, CA

Built 1969 Load: 24.3 t ADT: 20,000

OLIVE DRIVE

Fair

Over: BEARDSLEY CANAL

0.1 MI W AIRPORT DR, Kern, CA

Built 1968 Load: 24.3 t ADT: 13,000

ROBERTS LANE

Fair

Over: BEARDSLEY CANAL

NORTH OF OLIVE DRIVE, Kern, CA

Built 1968 Load: 24.3 t ADT: 9,000

34TH STREET

Fair

Over: KERN ISLAND CANAL

WEST OF UNION, Kern, CA

Built 1972 Load: 24.3 t ADT: 10,689

BELLE TERRACE WAY

Fair

Over: KERN ISLAND CANAL

EAST OF H STREET, Kern, CA

Built 1950 Load: 24.3 t ADT: 4,133

PLANZ ROAD

Fair

Over: KERN ISLAND CANAL

EAST OF SOUTH H ST, Kern, CA

Built 1952 Load: 24.3 t ADT: 14,700

PACHECO ROAD

Fair

Over: KERN ISLAND CANAL

EAST OF SOUTH H ST, Kern, CA

Built 1968 Load: 24.3 t ADT: 10,600

COLUMBUS AVE

Fair

Over: KERN ISLAND CANAL

0.2 MI W UNION AVE, Kern, CA

Built 1970 Load: 24.3 t ADT: 10,425

4TH STREET

Fair

Over: SANDY CREEK

SOUTH OF ASH STREET, Kern, CA

Built 1970 Load: 24.3 t ADT: 3,560

EMMONS PARK DRIVE

Fair

Over: SANDY CREEK

SOUTH OF ASH STREET, Kern, CA

Built 1970 Load: 24.3 t ADT: 500

TERRACE WAY

Fair

Over: KERN ISLAND CANAL

200 E CHESTER AVE, Kern, CA

Built 1958 Load: 24.3 t ADT: 4,960

WILLIAMS ST

Fair

Over: EAST SIDE CANAL

350 FT S MONTEREY ST, Kern, CA

Built 1967 Load: 24.3 t ADT: 5,300

ROBINSON ST

Fair

Over: EAST SIDE CANAL

SOUTH OF MONTEREY ST, Kern, CA

Built 1962 Load: 24.3 t ADT: 3,300

MILLER ST

Fair

Over: EAST SIDE CANAL

0.1 MI S MONTEREY ST, Kern, CA

Built 1960 Load: 24.3 t ADT: 6,300

GAGE ST

Fair

Over: EAST SIDE CANAL

0.1 MI S MONTEREY ST, Kern, CA

Built 1959 Load: 24.3 t ADT: 3,300

TULARE ST

Fair

Over: EAST SIDE CANAL

SOUTH OF MONTEREY ST, Kern, CA

Built 1950 Load: 24.3 t ADT: 4,300

VERNAL PLACE

Fair

Over: KERN ISLAND CANAL

0.1 MI N TERRACE WAY, Kern, CA

Built 1957 Load: 24.3 t ADT: 1,015

SOUTH GATE DR

Fair

Over: KERN ISLAND CANAL

EAST OF SOUTH H ST, Kern, CA

Built 1957 Load: 24.3 t ADT: 1,500

BEALE AVENUE

Fair

Over: EAST SIDE CANAL

SOUTH MONTEREY STREET, Kern, CA

Built 1966 Load: 24.3 t ADT: 10,000

HALEY ST

Fair

Over: EAST SIDE CANAL

SOUTH MONTEREY ST, Kern, CA

Built 1957 Load: 24.3 t ADT: 2,876

MOUNTAIN VIEW RD

Fair

Over: EAST SIDE CANAL

0.1 MI W OF VINELAND ROAD, Kern, CA

Built 1955 Load: 24.3 t ADT: 290

RANCHERIA ROAD

Fair

Over: KERN RIVER

0.7 MI NORTH OF SR 178, Kern, CA

Built 1952 Load: 24.6 t ADT: 412

STATE ROUTE 99 NB

Fair

Over: BEARDSLEY CANAL

06-KER-099-R28.39, Kern, CA

Built 1964 Load: 24.9 t ADT: 55,000

PALM AVENUE

Fair

Over: STATE ROUTE 99

06-KER-099-24.11-BKD, Kern, CA

Built 1963 Load: 25.9 t ADT: 6,000

GARDNER FIELD ROAD

Fair

Over: CALIFORNIA AQUEDUCT

0.5 MI EAST OF DUVALL ST, Kern, CA

Built 1968 Load: 25.9 t ADT: 1,072

CORCORAN RD

Fair

Over: POSO CREEK CHANNEL

7.4 MI N/O SR 46, Kern, CA

Built 1966 Load: 25.9 t ADT: 590

CADET ROAD

Fair

Over: CALIFORNIA AQUEDUCT

1.5 MI W GARDNER FIELD RD, Kern, CA

Built 1968 Load: 25.9 t ADT: 776

ALFRED HARREL HWY

Fair

Over: FAIRFAX ROAD

1.2 MI NE OF PANORAMA DR, Kern, CA

Built 1959 Load: 26.2 t ADT: 3,595

ALFRED HARREL HWY

Fair

Over: FAIRFAX ROAD

1.2 MI NE OF PANORAMA DR, Kern, CA

Built 1959 Load: 26.2 t ADT: 3,595

ALFRED HARREL HWY

Fair

Over: GOODMANVILLE ACCESS RD

1.5 MI NE OF FAIRFAX RD, Kern, CA

Built 1959 Load: 26.2 t ADT: 3,595

ALFRED HARREL HWY

Fair

Over: GOODMANVILLE ACCESS RD

1.5 MI NE OF FAIRFAX RD, Kern, CA

Built 1959 Load: 26.2 t ADT: 3,595

MERCED AVE

Fair

Over: UP RR

WEST OF S.H. 99, Kern, CA

Built 1968 Load: 26.2 t ADT: 760

SHERWOOD AVE

Fair

Over: STATE ROUTE 99

06-KER-099-49.30-MCF, Kern, CA

Built 1963 Load: 26.6 t ADT: 4,677

PERKINS AVE

Fair

Over: STATE ROUTE 99

06-KER-099-49.95-MCF, Kern, CA

Built 1963 Load: 26.6 t ADT: 440

CHESTER AVE NB

Fair

Over: KERN RIVER

0.3 MI S ROBERTS LANE, Kern, CA

Built 1978 Load: 26.9 t ADT: 9,973

LOKERN ROAD

Fair

Over: CALIFORNIA AQUEDUCT

1.5 MI WEST OF HWY 58, Kern, CA

Built 1967 Load: 27.2 t ADT: 2,400

STATE ROUTE 58

Fair

Over: CALIENTE CREEK OVERFLOW

06-KER-058-67.85, Kern, CA

Built 1960 Load: 27.5 t ADT: 10,000

STATE ROUTE 58

Fair

Over: CALIENTE CREEK OVERFLOW

06-KER-058-67.85, Kern, CA

Built 1960 Load: 27.5 t ADT: 13,000

DOYLE RANCH RD

Fair

Over: SOUTH FORK KERN RIVER

0.1 MI N OF RTE 178, Kern, CA

Built 1968 Load: 27.5 t ADT: 140

GOSFORD ROAD SB

Fair

Over: KERN RIVER CANAL

0.2 MI S TRUXTUN AVE, Kern, CA

Built 1984 Load: 27.5 t ADT: 17,700

LEBEC SERVICE ROAD

Fair

Over: INTERSTATE 5

06-KER-005-1.61, Kern, CA

Built 1964 Load: 28.2 t ADT: 2,370

AIRPORT DRIVE

Fair

Over: BEARDSLEY CANAL

0.1 MI S OF OLIVE DR, Kern, CA

Built 1951 Load: 28.5 t ADT: 25,500
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.