Total bridges
1,632
Public highway bridges in San Diego County
County profile · official public datasets
San Diego County, CA
1,632 public highway bridges tracked in the FHWA National Bridge Inventory: 52.8% rated Good, 44.2% Fair, 3.1% Poor.
- 1,632
- Public bridges
- 52.8%
- Good condition
- 3.1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
San Diego County pairs a top-10% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 9%
- lowest Poor share in state
- 3.1%
- Poor-condition share
- 1,632
- public highway bridges
- 1977
- 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.
San Diego County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, San Diego County ranks #5 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.1%). San Diego County, California contains 1,632 public highway bridges. Roughly 52.8% are rated “Good,” 44.2% “Fair,” and 3.1% “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
52.8%
861 of 1,632 rated 7-9
Fair condition
44.2%
721 of 1,632 rated 5-6
Poor condition
3.1%
50 of 1,632 rated 4 or below
In-state Poor-share rank
#5 of 58
Among California counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 1,632 NBI-tracked bridges by lowest applicable component rating.
Good 52.8% (861)
Fair 44.2% (721)
Poor 3.1% (50)
San Diego County's Poor-condition bridges carry 1,808,795 vehicle crossings a day
That is 3.2% of the county's reported daily bridge traffic on 3.1% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 36,176 crossings a day against 29,200 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 1,632 of 1,632 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
51.3% of San Diego County's bridges have passed the 50-year mark
838 of the 1,632 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 52.8% 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 13.8% of the county's Poor-condition bridge traffic
INTERSTATE 805 over TELEGRAPH CANYON DRAIN, built 1971, carries 250,000 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 50-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 1,808,795 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When San Diego County's bridges were built
1,632 bridges with a recorded construction year, grouped by decade
- 1900s 2
1900–1909
2 bridges
- 1910s 5
1910–1919
5 bridges
- 1920s 16
1920–1929
16 bridges
- 1930s 29
1930–1939
29 bridges
- 1940s 59
1940–1949
59 bridges
- 1950s 110
1950–1959
110 bridges
- 1960s
1960–1969
361 bridges
- 1970s
1970–1979
410 bridges
- 1980s
1980–1989
203 bridges
- 1990s
1990–1999
169 bridges
- 2000s
2000–2009
164 bridges
- 2010s 91
2010–2019
91 bridges
- 2020s 13
2020–2029
13 bridges
What this shows Construction peaked in the 1970s, when 410 of the county's bridges still in the inventory were built, which is 25.1% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1977, 7 years newer than the California average of 1970.
How San Diego County compares with California's closest counties by inventory size
The 5 California counties nearest San Diego County in number of bridges, with their condition splits. Its 3.1% Poor share is the 3rd-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1974 is in line with the group.
Showing the 5 closest of 57 California counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| San Diego County (this page) | 1,632 | 52.8% | 44.2% | 3.1% | 1977 |
| San Bernardino County | 1,422 | 41.9% | 52.1% | 6% | 1975 |
| Orange County | 1,164 | 53.2% | 43.8% | 3% | 1978 |
| Riverside County | 1,117 | 56.4% | 41.2% | 2.4% | 1977 |
| Santa Clara County | 964 | 38.3% | 56.1% | 5.6% | 1972 |
| Fresno County | 916 | 38.9% | 57.3% | 3.8% | 1969 |
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 San Diego 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 San Diego County, both outside California so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside CA (1,632 bridges here).
- Travis County, TX · 1,544 bridges
- Cook County, IL · 1,721 bridges
- Sedgwick County, KS · 1,333 bridges
- Allegheny County, PA · 1,294 bridges
Similar average build year
Nearest mean year-built outside CA (1977 here).
- King County, WA · avg 1977 · 1,238 bridges
- Shelby County, TN · avg 1977 · 1,077 bridges
- Chautauqua County, NY · avg 1977 · 559 bridges
- St. Clair County, IL · avg 1977 · 486 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (721)
INTERSTATE 15 NB
FairOver: VALLEY PARKWAY
11-SD-015-R30.63-ESD, San Diego, CA
Built 1977 Load: 56.7 t ADT: 90,500
OCEANVIEW BLVD
FairOver: SO. BRANCH CHOLLAS CREEK
0.25 MI E/O 40TH ST, San Diego, CA
Built 1982 Load: 56.7 t ADT: 10,300
INTERSTATE 8 WB
FairOver: LA POSTA CR LA POSTA RD
11-SD-008-R56.83L, San Diego, CA
Built 1974 Load: 57.3 t ADT: 8,350
S5-PERSHING DR OFF
FairOver: I 5 CONNS ON&OFF RAMPS
11-SD-005-R15.43-SD, San Diego, CA
Built 1963 Load: 57.7 t ADT: 12,200
SEA CLIFF BLVD
FairOver: WEST MISSION BAY DRIVE
0.4MI N/O RTE I-8, San Diego, CA
Built 1972 Load: 58.0 t ADT: 6,066
INTERSTATE 805 SB
FairOver: SWEETWATER RIVER
11-SD-805-8.66, San Diego, CA
Built 1975 Load: 59.3 t ADT: 204,000
STATE ROUTE 94 EB
FairOver: CAMPO ROAD-N125 ON RAMP
11-SD-094-R10.49R-LMSA, San Diego, CA
Built 1976 Load: 59.3 t ADT: 73,000
EL DORADO PKWY
FairOver: LOS COCHES CREEK
300 S OF HWY 8, San Diego, CA
Built 1983 Load: 59.3 t ADT: 156
INTERSTATE 8 EB
FairOver: LA POSTA CR LA POSTA RD
11-SD-008-R56.78R, San Diego, CA
Built 1974 Load: 59.6 t ADT: 8,350
STATE ROUTE 76 WB
FairOver: MISSION AVE
11-SD-076-R4.55-OCN, San Diego, CA
Built 1999 Load: 59.9 t ADT: 23,000
STATE ROUTE 76 EB
FairOver: MISSION AVE
11-SD-076-R4.55-OCN, San Diego, CA
Built 1999 Load: 60.3 t ADT: 23,000
WASHINGTON STREET
FairOver: STATE ROUTE 163
11-SD-163-2.75-SD, San Diego, CA
Built 1942 Load: 60.9 t ADT: 29,356
WILDCAT CANYON RD
FairOver: SAN VICENTE CREEK
550 FT S/O SAN VICENTE RD, San Diego, CA
Built 1984 Load: 62.9 t ADT: 6,074
INTERSTATE 5
FairOver: SOUTH CHOLLAS CREEK
11-SD-005-R12.43-SD, San Diego, CA
Built 1963 Load: 63.8 t ADT: 164,000
INTERSTATE 5 SB
FairOver: SAN LUIS REY RIVER
11-SD-005-R54.04-OCN, San Diego, CA
Built 1971 Load: 63.8 t ADT: 78,500
WILLOW GLEN RD
FairOver: RAINBOW CREEK
1.4MI N/O MISSION RD, San Diego, CA
Built 1984 Load: 64.2 t ADT: 329
WEST HILLS PKWY
FairOver: SAN DIEGO RIVER
0.3 MI N/O MISSION GORGE, San Diego, CA
Built 1980 Load: 65.1 t ADT: 22,300
BALBOA AVE
FairOver: INTERSTATE 805 & RAMPS
11-SD-805-21.65-SD, San Diego, CA
Built 1972 Load: 67.4 t ADT: 56,000
INTERSTATE 5
FairOver: SANTA MARGARITA RIVER
11-SD-005-R56.43L-OCN, San Diego, CA
Built 1967 Load: 73.2 t ADT: 70,250
INTERSTATE 5
FairOver: SANTA MARGARITA RIVER
11-SD-005-R56.43R-OCN, San Diego, CA
Built 1967 Load: 74.2 t ADT: 132,000
CARLSBAD BLVD NB
FairOver: LAS ENCINAS CREEK
0.6MI S/O PALOMAR AIRPORT, San Diego, CA
Built 1951 Load: 99.9 t ADT: 12,300
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.