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.
Good-condition bridges (335)
BOUNDARY FLAT RD
GoodOver: STATE ROUTE 178
06-KER-178-R39.88, Kern, CA
Built 1968 Load: 39.5 t ADT: 5
INTERSTATE 5 SB
GoodOver: SR 99 TRUCK RAMP SB
06-KER-005-R15.51L, Kern, CA
Built 1972 Load: 39.9 t ADT: 34,500
DWR SERVICE ROAD
GoodOver: INTERSTATE 5
06-KER-005-45.13, Kern, CA
Built 1969 Load: 40.2 t ADT: 18
DAWN ROAD
GoodOver: STATE ROUTE 14
09-KER-014-R6.12, Kern, CA
Built 1972 Load: 40.2 t ADT: 300
BACKUS ROAD
GoodOver: STATE ROUTE 14
09-KER-014-R9.14, Kern, CA
Built 1972 Load: 40.2 t ADT: 200
BRUNDAGE LANE
GoodOver: STATE ROUTE 99
06-KER-099-23.62-BKD, Kern, CA
Built 1963 Load: 40.5 t ADT: 18,000
E178-UNION AVE OFF
GoodOver: UP RR & ESPEE STREET
06-KER-178-R2.09-BKD, Kern, CA
Built 1967 Load: 40.5 t ADT: 4,850
UTILITY SERVICE RD
GoodOver: INTERSTATE 5
06-KER-005-42.97, Kern, CA
Built 1969 Load: 40.5 t ADT: 18
BUTTONWILLOW DR
GoodOver: INTERSTATE 5
06-KER-005-58.01, Kern, CA
Built 1969 Load: 41.1 t ADT: 35
STERLING ROAD
GoodOver: SR 58
06-KER-058-R57.93, Kern, CA
Built 1974 Load: 41.8 t ADT: 1,400
STATE HWY 58 WB
GoodOver: BNSF RY
09-KER-058-R141.49, Kern, CA
Built 1971 Load: 42.4 t ADT: 15,700
W178-N204 CONNECTR
GoodOver: Q STREET
06-KER-178-R1.97-BKD, Kern, CA
Built 1967 Load: 42.8 t ADT: 8,500
CAMERON ROAD
GoodOver: STATE ROUTE 58
09-KER-058-R101.56, Kern, CA
Built 1970 Load: 43.4 t ADT: 600
ZERKER RD
GoodOver: CALLOWAY BYPASS CANAL
1.8 MI N 7TH STANDARD RD, Kern, CA
Built 1961 Load: 43.7 t ADT: 2,650
7TH STANDARD RD
GoodOver: INTERSTATE 5
06-KER-005-56.64, Kern, CA
Built 1969 Load: 44.1 t ADT: 2,300
GARDNER FIELD ROAD
GoodOver: SANDY CREEK
0.9 MI E DUVALL ST, Kern, CA
Built 1973 Load: 44.4 t ADT: 1,072
SR 178
GoodOver: 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
GoodOver: KERN RIV FLOOD CANAL RD
06-KER-005-71.56, Kern, CA
Built 1967 Load: 45.4 t ADT: 16,000
NILES ST
GoodOver: STATE ROUTE 178
06-KER-178-R2.81-BKD, Kern, CA
Built 1967 Load: 45.4 t ADT: 4,880
BUTTONWILLOW DRIVE
GoodOver: WESTSIDE CANAL
0.5 MI SOUTH OF BRITE RD, Kern, CA
Built 1972 Load: 46.0 t ADT: 1,450
CLAY MINE ROAD
GoodOver: STATE ROUTE 58
09-KER-058-R132.04, Kern, CA
Built 1974 Load: 48.0 t ADT: 500
STATE ROUTE 58
GoodOver: MADISON STREET
06-KER-058-R54.91, Kern, CA
Built 1976 Load: 48.3 t ADT: 42,000
MT VERNON AVE
GoodOver: STATE ROUTE 178
06-KER-178-R4.59-BKD, Kern, CA
Built 1970 Load: 49.6 t ADT: 28,261
SOUTH H ST
GoodOver: SR 58
06-KER-058-R53.39-BKD, Kern, CA
Built 1976 Load: 52.2 t ADT: 10,000
POSO FLAT ROAD
GoodOver: POSO CREEK
3.5 MI E OF GRANITE RD, Kern, CA
Built 1989 Load: 52.2 t ADT: 120
STATE ROUTE 58 EB
GoodOver: TVRR
06-KER-058-R55.19, Kern, CA
Built 1976 Load: 52.8 t ADT: 42,000
STATE ROUTE 58 EB
GoodOver: UP RR & BNSF RY
09-KER-058-R99.26, Kern, CA
Built 1970 Load: 53.5 t ADT: 10,000
MUROC RD
GoodOver: STATE ROUTE 58
09-KER-058-R129.67, Kern, CA
Built 1974 Load: 53.8 t ADT: 1,200
FLOWER ST
GoodOver: STATE ROUTE 178
06-KER-178-R3.33-BKD, Kern, CA
Built 1967 Load: 54.8 t ADT: 1,952
STATE ROUTE 58 EB
GoodOver: UP RR TEHACHAPI CREEK
09-KER-058-82.64, Kern, CA
Built 1962 Load: 55.7 t ADT: 10,600
STATE ROUTE 58 WB
GoodOver: TVRR
06-KER-058-R55.20, Kern, CA
Built 1976 Load: 57.3 t ADT: 33,500
LEBEC ROAD
GoodOver: CUDDY CREEK
0.06 MI N FRAZIER MTN RD, Kern, CA
Built 1982 Load: 61.6 t ADT: 3,800
LAKEWOOD PLACE
GoodOver: CUDDY CREEK
0.02 MI N LAKEWOOD DR, Kern, CA
Built 1979 Load: 62.5 t ADT: 835
BRUNDAGE LN & OAK
GoodOver: W58-N99 CONNECTOR RAMP
06-KER-058-R52.38-BKD, Kern, CA
Built 1976 Load: 76.8 t ADT: 20,000
COFFEE ROAD NB
GoodOver: KERN RIVER
0.2 MI N TRUXTUN AVE, Kern, CA
Built 1981 Load: 88.8 t ADT: 30,000
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.