Total bridges
16
Public highway bridges in North Slope County
County profile · official public datasets
North Slope County, AK
16 public highway bridges tracked in the FHWA National Bridge Inventory: 62.5% rated Good, 31.3% Fair, 6.3% Poor.
- 16
- Public bridges
- 62.5%
- Good condition
- 6.3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
North Slope County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 41%
- lowest Poor share in state
- 6.3%
- Poor-condition share
- 16
- public highway bridges
- 1996
- 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.
North Slope County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, North Slope County ranks #11 of 27 Alaska counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.3%). North Slope County, Alaska contains 16 public highway bridges. Roughly 62.5% are rated “Good,” 31.3% “Fair,” and 6.3% “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
62.5%
10 of 16 rated 7-9
Fair condition
31.3%
5 of 16 rated 5-6
Poor condition
6.3%
1 of 16 rated 4 or below
In-state Poor-share rank
#11 of 27
Among Alaska counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 16 NBI-tracked bridges by lowest applicable component rating.
Good 62.5% (10)
Fair 31.3% (5)
Poor 6.3% (1)
6.3% of North Slope County's bridges have passed the 50-year mark
1 of the 16 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 62.5% 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.
When North Slope County's bridges were built
16 bridges with a recorded construction year, grouped by decade
- 1970s 1
1970–1979
1 bridges
- 1980s
1980–1989
4 bridges
- 1990s
1990–1999
4 bridges
- 2000s
2000–2009
2 bridges
- 2010s
2010–2019
5 bridges
What this shows Construction peaked in the 2010s, when 5 of the county's bridges still in the inventory were built, which is 31.3% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year is 1996, 7 years newer than the Alaska average of 1989.
How North Slope County compares with Alaska's closest counties by inventory size
The 5 Alaska counties nearest North Slope County in number of bridges, with their condition splits. Its 6.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1996 against a peer-group mean of 1991 is 5 years newer.
Showing the 5 closest of 26 Alaska counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Haines County | 20 | 45% | 50% | 5% | 1994 |
| Aleutians East County | 16 | 31.3% | 62.5% | 6.3% | 2000 |
| North Slope County (this page) | 16 | 62.5% | 31.3% | 6.3% | 1996 |
| Yakutat City and County | 15 | 46.7% | 40% | 13.3% | 1978 |
| Bethel County | 13 | 53.8% | 38.5% | 7.7% | 1997 |
| Lake and Peninsula County | 10 | 50% | 40% | 10% | 1988 |
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 North Slope 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 North Slope County, both outside Alaska so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside AK (16 bridges here).
- Alamosa County, CO · 16 bridges
- Grant County, KS · 16 bridges
- Cataño County, PR · 16 bridges
- Comerío County, PR · 16 bridges
Similar average build year
Nearest mean year-built outside AK (1996 here).
- Clark County, NV · avg 1996 · 1,141 bridges
- Hamilton County, IN · avg 1996 · 454 bridges
- Hays County, TX · avg 1996 · 272 bridges
- Jackson County, MS · avg 1996 · 268 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (5)
DALTON HIGHWAY
FairOver: WEST FORK N FK CHANDALAR
MILE POINT 243.7, North Slope, AK
Built 1982 Load: 44.5 t ADT: 110
DALTON HIGHWAY
FairOver: DAN CREEK
MILE POINT 331.0, North Slope, AK
Built 1982 Load: 45.4 t ADT: 130
DALTON HIGHWAY
FairOver: KUPARUK RIVER
MILE POINT 289.2, North Slope, AK
Built 1994 Load: 54.3 t ADT: 130
DALTON HIGHWAY
FairOver: TREVOR CREEK
MILE POINT 259.0, North Slope, AK
Built 1982 Load: 65.8 t ADT: 130
DALTON HIGHWAY
FairOver: MARX CREEK
MILE POINT 253.8, North Slope, AK
Built 1972 Load: 99.9 t ADT: 130
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.