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.

All bridges (668)

W178-N204 CONNECTR

Good

Over: Q STREET

06-KER-178-R1.97-BKD, Kern, CA

Built 1967 Load: 42.8 t ADT: 8,500

CAMERON ROAD

Good

Over: STATE ROUTE 58

09-KER-058-R101.56, Kern, CA

Built 1970 Load: 43.4 t ADT: 600

ZERKER RD

Good

Over: CALLOWAY BYPASS CANAL

1.8 MI N 7TH STANDARD RD, Kern, CA

Built 1961 Load: 43.7 t ADT: 2,650

7TH STANDARD RD

Good

Over: INTERSTATE 5

06-KER-005-56.64, Kern, CA

Built 1969 Load: 44.1 t ADT: 2,300

GARDNER FIELD ROAD

Good

Over: SANDY CREEK

0.9 MI E DUVALL ST, Kern, CA

Built 1973 Load: 44.4 t ADT: 1,072

SR 178

Good

Over: SR 178 SPUR WB\24TH ST

06-KER-178-R1.90-BKD, Kern, CA

Built 1967 Load: 45.0 t ADT: 51,000

INTERSTATE 5 NB

Good

Over: KERN RIV FLOOD CANAL RD

06-KER-005-71.56, Kern, CA

Built 1967 Load: 45.4 t ADT: 16,000

NILES ST

Good

Over: STATE ROUTE 178

06-KER-178-R2.81-BKD, Kern, CA

Built 1967 Load: 45.4 t ADT: 4,880

BUTTONWILLOW DRIVE

Good

Over: WESTSIDE CANAL

0.5 MI SOUTH OF BRITE RD, Kern, CA

Built 1972 Load: 46.0 t ADT: 1,450

CLAY MINE ROAD

Good

Over: STATE ROUTE 58

09-KER-058-R132.04, Kern, CA

Built 1974 Load: 48.0 t ADT: 500

STATE ROUTE 58

Good

Over: MADISON STREET

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

Built 1976 Load: 48.3 t ADT: 42,000

MT VERNON AVE

Good

Over: STATE ROUTE 178

06-KER-178-R4.59-BKD, Kern, CA

Built 1970 Load: 49.6 t ADT: 28,261

SOUTH H ST

Good

Over: SR 58

06-KER-058-R53.39-BKD, Kern, CA

Built 1976 Load: 52.2 t ADT: 10,000

POSO FLAT ROAD

Good

Over: POSO CREEK

3.5 MI E OF GRANITE RD, Kern, CA

Built 1989 Load: 52.2 t ADT: 120

STATE ROUTE 58 EB

Good

Over: TVRR

06-KER-058-R55.19, Kern, CA

Built 1976 Load: 52.8 t ADT: 42,000

STATE ROUTE 58 EB

Good

Over: UP RR & BNSF RY

09-KER-058-R99.26, Kern, CA

Built 1970 Load: 53.5 t ADT: 10,000

MUROC RD

Good

Over: STATE ROUTE 58

09-KER-058-R129.67, Kern, CA

Built 1974 Load: 53.8 t ADT: 1,200

FLOWER ST

Good

Over: STATE ROUTE 178

06-KER-178-R3.33-BKD, Kern, CA

Built 1967 Load: 54.8 t ADT: 1,952

STATE ROUTE 58 EB

Good

Over: UP RR TEHACHAPI CREEK

09-KER-058-82.64, Kern, CA

Built 1962 Load: 55.7 t ADT: 10,600

STATE ROUTE 58 WB

Good

Over: TVRR

06-KER-058-R55.20, Kern, CA

Built 1976 Load: 57.3 t ADT: 33,500

LEBEC ROAD

Good

Over: CUDDY CREEK

0.06 MI N FRAZIER MTN RD, Kern, CA

Built 1982 Load: 61.6 t ADT: 3,800

LAKEWOOD PLACE

Good

Over: CUDDY CREEK

0.02 MI N LAKEWOOD DR, Kern, CA

Built 1979 Load: 62.5 t ADT: 835

BRUNDAGE LN & OAK

Good

Over: W58-N99 CONNECTOR RAMP

06-KER-058-R52.38-BKD, Kern, CA

Built 1976 Load: 76.8 t ADT: 20,000

COFFEE ROAD NB

Good

Over: KERN RIVER

0.2 MI N TRUXTUN AVE, Kern, CA

Built 1981 Load: 88.8 t ADT: 30,000

RIVER ROAD

Poor

Over: KERN RIVER PARK

EAST OF HARBOR ROAD, Kern, CA

Built 1934 Load: 16.8 t ADT: 450

STATE ROUTE 46

Poor

Over: GOOSE LAKE CANAL

06-KER-046-35.13, Kern, CA

Built 1956 Load: 18.1 t ADT: 6,100

PERKINS AVE

Poor

Over: UP RR

0.25 MI W BROWNING RD, Kern, CA

Built 1963 Load: 21.7 t ADT: 3,970

WILSON ROAD

Poor

Over: STATE ROUTE 99

06-KER-099-22.11-BKD, Kern, CA

Built 1962 Load: 24.6 t ADT: 40,000

BAKERSFLD-GLEN RD

Poor

Over: GRANITE CANYON CREEK

0.5 MI N/O RND MTN RD, Kern, CA

Built 1948 Load: 24.9 t ADT: 930

WHISLER ROAD

Poor

Over: POSO CREEK

2.9 MI E STATE HWY 43, Kern, CA

Built 1958 Load: 25.3 t ADT: 950

KERNVILLE RD

Poor

Over: KERN RIVER

EAST OF BUENA VISTA DR, Kern, CA

Built 1969 Load: 26.6 t ADT: 4,100

SIERRA WAY

Poor

Over: SOUTH FORK KERN RIVER

1.0 MI N/O SH 178, Kern, CA

Built 1958 Load: 27.2 t ADT: 1,060

STATE ROUTE 99

Poor

Over: HIGH ST & UP RR

06-KER-099-57.10-DLN, Kern, CA

Built 1955 Load: 27.9 t ADT: 53,000

STATE ROUTE 223

Poor

Over: STATE ROUTE 99

06-KER-223-R10.51, Kern, CA

Built 1962 Load: 27.9 t ADT: 4,700

PANORAMA DRIVE

Poor

Over: MANOR STREET

0.15 MI FROM COLUMBUS AV, Kern, CA

Built 1957 Load: 29.8 t ADT: 12,000

KIMBERLINA RD

Poor

Over: UP RR

WEST OF SH 99, Kern, CA

Built 1968 Load: 30.1 t ADT: 3,200

ELK HILLS ROAD

Poor

Over: CALIFORNIA AQUEDUCT

1.5 MI SOUTH OF BRITE RD, Kern, CA

Built 1968 Load: 30.1 t ADT: 1,253

LOST HILLS ROAD

Poor

Over: CALIFORNIA AQUEDUCT

0.7 MI S OF S.H. 46, Kern, CA

Built 1966 Load: 31.1 t ADT: 3,561

LAKE ISABELLA RD

Poor

Over: BOREL CANAL

0.75 MI N OF NUGGET AVE, Kern, CA

Built 1948 Load: 31.4 t ADT: 5,400

HOUGHTON ROAD

Poor

Over: STATE ROUTE 99

06-KER-099-15.43, Kern, CA

Built 1962 Load: 32.1 t ADT: 3,515

PANAMA LANE

Poor

Over: STATE ROUTE 99

06-KER-099-19.54, Kern, CA

Built 1962 Load: 32.4 t ADT: 44,034

LERDO HIGHWAY

Poor

Over: INTERSTATE 5

06-KER-005-62.60, Kern, CA

Built 1967 Load: 32.4 t ADT: 3,000

STATE ROUTE 166

Poor

Over: CALIFORNIA AQUEDUCT

06-KER-166-17.44, Kern, CA

Built 1968 Load: 32.4 t ADT: 2,100

SHERWOOD AVE

Poor

Over: UP RR

0.1 MI W SAN JUAN ST, Kern, CA

Built 1963 Load: 32.4 t ADT: 3,060

N 10TH STREET

Poor

Over: SANDY CREEK

0.22 MI S OF ASH STREET, Kern, CA

Built 1979 Load: 32.4 t ADT: 7,590

TEJON HIGHWAY

Poor

Over: BEAR VALLEY CREEK

2.3 MI S OF HIGHWAY 223, Kern, CA

Built 1983 Load: 32.4 t ADT: 710

7TH STANDARD ROAD

Poor

Over: BNSF RY SANTA FE WAY

6 MI WEST OF SR99, Kern, CA

Built 2010 Load: 32.4 t ADT: 7,300

BEALE AVE

Poor

Over: UP RR SUMNER ST KENTUCKY

SOUTH MONTEREY ST, Kern, CA

Built 1960 Load: 33.0 t ADT: 14,615

INTERSTATE 5 SB

Poor

Over: KERN RIVER

06-KER-005-42.00, Kern, CA

Built 1969 Load: 34.0 t ADT: 15,000

INTERSTATE 5 NB

Poor

Over: KERN RIVER

06-KER-005-42.00, Kern, CA

Built 1969 Load: 34.0 t ADT: 15,000
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.