Total bridges
668
Public highway bridges in Kern County
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.
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
- 1910s 5
1910–1919
5 bridges
- 1920s 6
1920–1929
6 bridges
- 1930s 19
1930–1939
19 bridges
- 1940s 36
1940–1949
36 bridges
- 1950s
1950–1959
81 bridges
- 1960s
1960–1969
200 bridges
- 1970s
1970–1979
139 bridges
- 1980s 41
1980–1989
41 bridges
- 1990s 39
1990–1999
39 bridges
- 2000s 42
2000–2009
42 bridges
- 2010s 52
2010–2019
52 bridges
- 2020s 8
2020–2029
8 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).
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Sacramento County | 740 | 50.9% | 45.7% | 3.4% | 1973 |
| Kern County (this page) | 668 | 50.1% | 43.3% | 6.6% | 1972 |
| Alameda County | 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 |
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).
- Berks County, PA · 667 bridges
- St. Louis County, MN · 663 bridges
- Hinds County, MS · 663 bridges
- Jefferson County, KY · 662 bridges
Similar average build year
Nearest mean year-built outside CA (1972 here).
- Madison County, AL · avg 1972 · 710 bridges
- York County, PA · avg 1972 · 569 bridges
- Middlesex County, NJ · avg 1972 · 563 bridges
- Saunders County, NE · avg 1972 · 506 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (668)
HERRING RD
FairOver: INTERSTATE 5
06-KER-005-28.16, Kern, CA
Built 1967 Load: 8.1 t ADT: 25
WOOLLOMES AVE
FairOver: FRIANT-KERN CANAL
0.3 MI EAST OF ZACHARY AV, Kern, CA
Built 1949 Load: 10.4 t ADT: 470
INTERSTATE 5 NB
FairOver: CALIFORNIA AQUEDUCT
06-KER-005-12.47, Kern, CA
Built 1967 Load: 13.0 t ADT: 24,375
POND RD
FairOver: FRIANT-KERN CANAL
0.3 MI EAST OF ZACHARY AV, Kern, CA
Built 1950 Load: 15.2 t ADT: 660
LERDO HIGHWAY
FairOver: UP RR
0.2 MI E OF ZERKER RD, Kern, CA
Built 1961 Load: 15.9 t ADT: 10,110
PETERSON RD
FairOver: FRIANT-KERN CANAL
0.3 MI WEST OF ZACHARY AV, Kern, CA
Built 1949 Load: 15.9 t ADT: 150
STATE ROUTE 99
FairOver: LERDO CANAL
06-KER-099-37.22, Kern, CA
Built 1913 Load: 16.2 t ADT: 90,000
STATE ROUTE 33
FairOver: WASP WASH
06-KER-033-37.89, Kern, CA
Built 1940 Load: 16.2 t ADT: 1,400
STATE ROUTE 119
FairOver: BUENA VISTA SLOUGH
06-KER-119-14.98, Kern, CA
Built 1931 Load: 16.2 t ADT: 10,400
34TH STREET
FairOver: EAST SIDE CANAL
WEST OF UNION AVE, Kern, CA
Built 1935 Load: 16.2 t ADT: 10,689
KING BAKER KERN ST
FairOver: EAST SIDE CANAL
AT LAKE STREET, Kern, CA
Built 1940 Load: 16.2 t ADT: 3,877
CHESTER AVE
FairOver: LEVEE CANAL
NORTH OF 42ND ST, Kern, CA
Built 1930 Load: 16.2 t ADT: 15,625
4TH STREET
FairOver: KERN ISLAND CANAL
0.3 MI W OF UNION AVE, Kern, CA
Built 1940 Load: 16.2 t ADT: 4,402
8TH STREET
FairOver: KERN ISLAND CANAL
EAST OF R ST, Kern, CA
Built 1936 Load: 16.2 t ADT: 7,541
ALTA VISTA DR
FairOver: EAST SIDE CANAL
SOUTH OF MONTEREY ST, Kern, CA
Built 1947 Load: 16.2 t ADT: 3,600
N STREET
FairOver: KERN ISLAND CANAL
150 FT N OF BRUNDAGE LN, Kern, CA
Built 1948 Load: 16.2 t ADT: 4,794
BRUNDAGE LANE
FairOver: KERN ISLAND CNL CNTRL BR
0.1 MI E/O P STREET, Kern, CA
Built 1915 Load: 16.2 t ADT: 4,016
BRUNDAGE LANE
FairOver: KERN ISLAND CANAL
WEST OF N STREET, Kern, CA
Built 1915 Load: 16.2 t ADT: 4,016
VALPREDO AVE
FairOver: INTERSTATE 5
06-KER-005-21.17, Kern, CA
Built 1967 Load: 16.5 t ADT: 250
9TH AVE
FairOver: FRIANT-KERN CANAL
0.6 MI EAST OF ZACHARY AV, Kern, CA
Built 1955 Load: 16.5 t ADT: 390
ZACHARY AVE
FairOver: FRIANT-KERN CANAL
0.4 MI SOUTH OF POND RD, Kern, CA
Built 1949 Load: 16.5 t ADT: 150
TWISSELMAN RD
FairOver: INTERSTATE 5
06-KER-005-82.35, Kern, CA
Built 1970 Load: 18.1 t ADT: 350
STATE ROUTE 46
FairOver: MAIN DRAIN CANAL
06-KER-046-34.63, Kern, CA
Built 1956 Load: 18.5 t ADT: 6,100
COUNTY LINE RD
FairOver: INTERSTATE 5
06-KER-005-87.02, Kern, CA
Built 1970 Load: 18.8 t ADT: 29
SABODAN ST
FairOver: INTERSTATE 5
06-KER-005-17.58, Kern, CA
Built 1967 Load: 19.1 t ADT: 35
MANOR STREET SB
FairOver: KERN RIVER
0.2 MI S ROBERTS LANE, Kern, CA
Built 1954 Load: 19.4 t ADT: 10,750
MANOR STREET NB
FairOver: KERN RIVER
0.2 MI S ROBERTS LANE, Kern, CA
Built 1957 Load: 19.4 t ADT: 10,750
BROWN-INYOKERN RD
FairOver: AIRPORT WASH
1.2 MI N OF RTE 178, Kern, CA
Built 1945 Load: 19.4 t ADT: 2,050
STATE ROUTE 119
FairOver: WEED CREEK
06-KER-119-4.41, Kern, CA
Built 1936 Load: 21.1 t ADT: 7,400
STATE ROUTE 119
FairOver: BROAD CREEK
06-KER-119-4.65, Kern, CA
Built 1936 Load: 21.4 t ADT: 9,700
UNIT 1/UNIT 2 DIKE
FairOver: MARSH UNIT 1/MARSH UNT 2
2.0 MI SSW OF HDQTRS, Kern, CA
Built 1970 Load: 21.6 t ADT: 15
WHISLER ROAD
FairOver: STATE ROUTE 99
06-KER-099-R47.37, Kern, CA
Built 1970 Load: 21.7 t ADT: 900
INTERSTATE 5 SB
FairOver: CALIFORNIA AQUEDUCT
06-KER-005-12.47, Kern, CA
Built 1967 Load: 21.7 t ADT: 24,375
UNIT 2/UNIT 3 DIKE
FairOver: MARSH UNIT 2/MARSH UNT 3
0.8 MI SSW OF HDQTRS, Kern, CA
Built 1970 Load: 21.8 t ADT: 15
UNIT2/UNIT 6B DIKE
FairOver: MARSH UNT 2/MARSH UNT 6B
1.2 MI SW OF HDQTRS, Kern, CA
Built 1970 Load: 21.8 t ADT: 15
CECIL AVE
FairOver: FRIANT-KERN CANAL
0.5 MI EAST OF ZACHARY AV, Kern, CA
Built 1949 Load: 22.7 t ADT: 2,260
STATE ROUTE 33
FairOver: SANDY CREEK
06-KER-033-19.51-TAF, Kern, CA
Built 1923 Load: 23.0 t ADT: 10,700
OILDALE DRIVE
FairOver: BEARDSLEY CANAL
0.04 MI S OF DECATUR DR, Kern, CA
Built 1981 Load: 23.0 t ADT: 5,300
STATE ROUTE 178
FairOver: HILLSIDE
06-KER-178-13.74, Kern, CA
Built 1923 Load: 23.3 t ADT: 4,350
MT VERNON AVE
FairOver: UP RR BNSF RY EDISON HWY
0.3 MI N CALIFORNIA ST., Kern, CA
Built 1960 Load: 23.3 t ADT: 31,500
BROWN-INYOKERN RD
FairOver: LITTLE DIXIE WASH
2 MI S OF RTE 178, Kern, CA
Built 1945 Load: 23.7 t ADT: 1,200
POND ROAD
FairOver: STATE ROUTE 99
06-KER-099-52.45, Kern, CA
Built 1960 Load: 24.0 t ADT: 660
OAK STREET
FairOver: BNSF RY & AMTRAK
0.1 MI N/O CALIFORNIA AVE, Kern, CA
Built 1939 Load: 24.0 t ADT: 24,433
BAKERSFLD-GLEN RD
FairOver: POSO CREEK
S OF ROUND MTN RD, Kern, CA
Built 1937 Load: 24.0 t ADT: 1,250
TUPMAN ROAD
FairOver: WESTSIDE CANAL
1.4 MI S OF STATION ROAD, Kern, CA
Built 1972 Load: 24.0 t ADT: 460
STATE ROUTE 166
FairOver: SAN EMIGDIO CREEK
06-KER-166-12.52, Kern, CA
Built 1929 Load: 24.3 t ADT: 3,300
STATE ROUTE 155
FairOver: POSO CREEK
06-KER-155-38.79, Kern, CA
Built 1943 Load: 24.3 t ADT: 300
STATE ROUTE 99 NB
FairOver: LERDO CANAL
06-KER-099-32.42, Kern, CA
Built 1936 Load: 24.3 t ADT: 90,000
STATE ROUTE 178
FairOver: HILLSIDE
06-KER-178-13.78, Kern, CA
Built 1922 Load: 24.3 t ADT: 4,350
STATE ROUTE 99
FairOver: LERDO CANAL
06-KER-099-R43.90L, Kern, CA
Built 1936 Load: 24.3 t ADT: 61,000
Read our methodology - how this data is sourced, computed, and verified.
Related
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.