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 99

Fair

Over: POSO CREEK

06-KER-099-44.54, Kern, CA

Built 1951 Load: 38.9 t ADT: 59,000

FRAZIER MTN ROAD

Fair

Over: CUDDY CREEK

0.5 MI E OF MONTEREY TRL, Kern, CA

Built 1970 Load: 38.9 t ADT: 6,300

UNION AVE-S99 ONRP

Fair

Over: STATE ROUTE 99

06-KER-099-10.93, Kern, CA

Built 1962 Load: 39.2 t ADT: 480

BAKER ST

Fair

Over: STATE ROUTE 178

06-KER-178-R3.16-BKD, Kern, CA

Built 1967 Load: 39.2 t ADT: 4,815

ELK HILLS ROAD

Fair

Over: BUENA VISTA CREEK

2.3 MI N OF SO. HO 119, Kern, CA

Built 1952 Load: 39.5 t ADT: 1,150

INTERSTATE 5 SB

Fair

Over: GRAPEVINE ROAD

06-KER-005-8.47L, Kern, CA

Built 1960 Load: 39.9 t ADT: 24,375

STATE ROUTE 119

Fair

Over: INTERSTATE 5

06-KER-119-19.74, Kern, CA

Built 1967 Load: 39.9 t ADT: 6,200

LEONARD AVE

Fair

Over: POSO CREEK

0.5 MI S ELMO HIGHWAY, Kern, CA

Built 1966 Load: 40.2 t ADT: 80

TRUXTUN AVENUE

Fair

Over: ST RTE 204 (UNION AVE)

06-KER-204-3.41-BKD, Kern, CA

Built 1959 Load: 40.5 t ADT: 13,403

STATE ROUTE 58

Fair

Over: WHITE WOLF EQUIPMENT UC

06-KER-058-75.17, Kern, CA

Built 1960 Load: 40.5 t ADT: 24,200

SILVER QUEEN ROAD

Fair

Over: STATE ROUTE 14

09-KER-014-R12.15, Kern, CA

Built 1972 Load: 40.5 t ADT: 20,200

LERDO HIGHWAY

Fair

Over: WESTSIDE CANAL

0.8 MI OF MAIN DRAIN RD, Kern, CA

Built 1968 Load: 40.5 t ADT: 1,200

WHEELER RIDGE RD N

Fair

Over: INTERSTATE 5

06-KER-005-13.52, Kern, CA

Built 1962 Load: 41.1 t ADT: 3,300

OLIVE AVENUE

Fair

Over: SOUTH TAFT CREEK

0.08 MI N CRYSTAL STREET, Kern, CA

Built 1963 Load: 41.8 t ADT: 510

ROSEDALE HWY

Fair

Over: KERN RIVER

0.2 MI EAST RTE 99, Kern, CA

Built 1963 Load: 41.8 t ADT: 26,000

WASHINGTON STREET

Fair

Over: SR 58

06-KER-058-R55.92-BKD, Kern, CA

Built 1974 Load: 42.1 t ADT: 2,613

SUPPLY ROW AVENUE

Fair

Over: SOUTH TAFT CREEK

0.18 MI N CRYSTAL STREET, Kern, CA

Built 1960 Load: 42.4 t ADT: 1,320

STATE ROUTE 178

Fair

Over: KERN RIVER

06-KER-178-R40.00, Kern, CA

Built 1971 Load: 42.8 t ADT: 4,200

15TH ST

Fair

Over: H STREET

H STREET, Kern, CA

Built 1989 Load: 42.8 t ADT: 1,356

AIRPORT DR-S99 ON

Fair

Over: SR 99 BUCK OWENS CALLOWY

06-KER-099-26.78, Kern, CA

Built 1963 Load: 43.4 t ADT: 15,800

ALTA VISTA DR

Fair

Over: ST RTE 178

06-KER-178-R2.74-BKD, Kern, CA

Built 1967 Load: 43.7 t ADT: 4,791

GRANITE RD

Fair

Over: POSO CREEK

0.8 MI S OF S.H. 155, Kern, CA

Built 1979 Load: 44.1 t ADT: 280

DAVID ROAD

Fair

Over: STATE ROUTE 99

06-KER-099-5.34, Kern, CA

Built 1960 Load: 44.4 t ADT: 2,683

STATE ROUTE 202

Fair

Over: STATE ROUTE 58

09-KER-202-11.99, Kern, CA

Built 1970 Load: 44.7 t ADT: 25,400

STATE ROUTE 99 NB

Fair

Over: UP RR

06-KER-099-R43.60R, Kern, CA

Built 1958 Load: 45.0 t ADT: 30,500

HUGHES LANE

Fair

Over: SR 58

06-KER-058-R52.89-BKD, Kern, CA

Built 1976 Load: 45.0 t ADT: 10,000

INTERSTATE 5 SB

Fair

Over: KERN RIV FLOOD CANAL RD

06-KER-005-71.56, Kern, CA

Built 1967 Load: 45.4 t ADT: 16,000

STATE HWY 58 EB

Fair

Over: BNSF RY

09-KER-058-R141.50, Kern, CA

Built 1971 Load: 45.7 t ADT: 15,400

UNION AVE-W178 ON

Fair

Over: UP RR & ESPEE STREET

06-KER-178-R2.09-BKD, Kern, CA

Built 1967 Load: 46.0 t ADT: 5,100

COFFEE ROAD NB

Fair

Over: CROSS VALLEY CANAL

JUST S OF ROUTE 58, Kern, CA

Built 1981 Load: 48.0 t ADT: 40,900

STATE ROUTE 58

Fair

Over: MADISON STREET

06-KER-058-R54.91, Kern, CA

Built 1976 Load: 48.3 t ADT: 33,500

STATE ROUTE 58 EB

Fair

Over: CACHE CREEK

09-KER-058-R107.60, Kern, CA

Built 1983 Load: 48.6 t ADT: 20,000

ST RT 43 (ENOS LN)

Fair

Over: KERN RIVER

06-KER-043-2.58, Kern, CA

Built 1977 Load: 49.2 t ADT: 5,450

BUTTONWILLOW DRIVE

Fair

Over: BUENA VISTA SLOUGH

0.6 MI S OF BRITE RD, Kern, CA

Built 1984 Load: 50.2 t ADT: 1,450

STATE ROUTE 178

Fair

Over: KERN RIVER

06-KER-178-R41.16, Kern, CA

Built 1971 Load: 56.1 t ADT: 4,200

STATE ROUTE 14 SB

Fair

Over: UP RR & BNSF RY

09-KER-014-R15.33, Kern, CA

Built 1990 Load: 60.9 t ADT: 8,975

ALFRED HARRELL HWY

Fair

Over: ALFRED HARRELL HWY

0.4 MI E CHINA GRADE LOOP, Kern, CA

Built 1957 Load: 61.9 t ADT: 7,250

KIMBERLINA RD

Fair

Over: LERDO CANAL

0.7 MI W OF DRIVER RD, Kern, CA

Built 1985 Load: 65.1 t ADT: 3,000

EDISON HIGHWAY

Fair

Over: EAST SIDE CANAL

EAST OF WEBSTER ST, Kern, CA

Built 1955 Load: 97.2 t ADT: 6,900
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.