Total bridges
237
Public highway bridges in Hawaii County
County profile · official public datasets
Hawaii County, HI
237 public highway bridges tracked in the FHWA National Bridge Inventory: 44.7% rated Good, 51.1% Fair, 4.2% Poor.
- 237
- Public bridges
- 44.7%
- Good condition
- 4.2%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Hawaii County pairs a top-quartile lowest Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- Top 25%
- lowest Poor share in state
- 4.2%
- Poor-condition share
- 237
- public highway bridges
- 1956
- 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.
Hawaii County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Hawaii County ranks #1 of 4 Hawaii counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.2%). Hawaii County, Hawaii contains 237 public highway bridges. Roughly 44.7% are rated “Good,” 51.1% “Fair,” and 4.2% “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
44.7%
106 of 237 rated 7-9
Fair condition
51.1%
121 of 237 rated 5-6
Poor condition
4.2%
10 of 237 rated 4 or below
In-state Poor-share rank
#1 of 4
Among Hawaii counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 237 NBI-tracked bridges by lowest applicable component rating.
Good 44.7% (106)
Fair 51.1% (121)
Poor 4.2% (10)
Hawaii County's Poor-condition bridges carry 24,405 vehicle crossings a day
That is 1.9% of the county's reported daily bridge traffic on 4.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,441 crossings a day against 6,753 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 235 of 237 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
77.2% of Hawaii County's bridges have passed the 50-year mark
183 of the 237 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 44.7% 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 39.3% of the county's Poor-condition bridge traffic
PAUAHI ST over PAUAHI ST-WAIOLAMA CANAL, built 1949, carries 9,600 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 10-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 24,405 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Hawaii County's bridges were built
237 bridges with a recorded construction year, grouped by decade
- 1900s 4
1900–1909
4 bridges
- 1910s 11
1910–1919
11 bridges
- 1920s
1920–1929
25 bridges
- 1930s
1930–1939
40 bridges
- 1940s 13
1940–1949
13 bridges
- 1950s
1950–1959
34 bridges
- 1960s
1960–1969
33 bridges
- 1970s
1970–1979
31 bridges
- 1980s
1980–1989
19 bridges
- 1990s 8
1990–1999
8 bridges
- 2000s 13
2000–2009
13 bridges
- 2010s 3
2010–2019
3 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1930s, when 40 of the county's bridges still in the inventory were built, which is 16.9% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1956, 5 years older than the Hawaii average of 1961.
How Hawaii County compares with Hawaii's closest counties by inventory size
The 3 Hawaii counties nearest Hawaii County in number of bridges, with their condition splits. Its 4.2% Poor share is the 1st-lowest of these 4. Its average build year of 1956 against a peer-group mean of 1960 is in line with the group.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Honolulu County | 682 | 35.8% | 57.3% | 6.9% | 1963 |
| Hawaii County (this page) | 237 | 44.7% | 51.1% | 4.2% | 1956 |
| Maui County | 185 | 33.5% | 60.5% | 5.9% | 1958 |
| Kauai County | 90 | 36.7% | 52.2% | 11.1% | 1959 |
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 Hawaii 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 Hawaii County, both outside Hawaii so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside HI (237 bridges here).
- Winona County, MN · 237 bridges
- DeKalb County, MO · 237 bridges
- Boone County, NE · 237 bridges
- Gallia County, OH · 237 bridges
Similar average build year
Nearest mean year-built outside HI (1956 here).
- Philadelphia County, PA · avg 1956 · 585 bridges
- Cochise County, AZ · avg 1956 · 501 bridges
- Hampden County, MA · avg 1956 · 428 bridges
- Stanislaus County, CA · avg 1956 · 386 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (10)
MAMALAHOA
PoorOver: MAMALAHOA/LAUHALA
TMK 4-2-02:20, Hawaii, HI
Built 1930 Load: 10.5 t ADT: 5
OLD MAMALAHOA HWY
PoorOver: OPEA STREAM
TMK: 3-2-001:018, Hawaii, HI
Built 1912 Load: 10.7 t ADT: 20
MAMALAHOA
PoorOver: MAMALAHOA/KOLEKOLE STRM
TMK 2-8-15:16, Hawaii, HI
Built 1929 Load: 13.6 t ADT: 40
OLD MAMALAHOA HWY
PoorOver: KAULA GULCH
TMK 4-1-01:15, Hawaii, HI
Built 1928 Load: 15.2 t ADT: 300
MAMALAHOA
PoorOver: MAMALAHOA/KAAHAKINI STRM
TMK 2-9-03:39, Hawaii, HI
Built 1929 Load: 18.1 t ADT: 40
MAMALAHOA
PoorOver: HANAWI STRM
TMK 2-7-09:13, Hawaii, HI
Built 1922 Load: 21.4 t ADT: 600
OLD MAMALAHOA HWY
PoorOver: KAWAINUI STREAM
TMK 2-7-11:2, Hawaii, HI
Built 1900 Load: 21.7 t ADT: 400
HAWAII BELT RD
PoorOver: HAKALAU STRM
0.98MI E/KAUNIHO RD, Hawaii, HI
Built 1953 Load: 30.5 t ADT: 6,700
HAWAII BELT RD
PoorOver: NANUE STRM
1.66MI W/KAUNIHO RD, Hawaii, HI
Built 1952 Load: 48.3 t ADT: 6,700
PAUAHI ST
PoorOver: PAUAHI ST-WAIOLAMA CANAL
400 S/Kam. Ave., Hawaii, HI
Built 1949 Load: 55.4 t ADT: 9,600
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.