Total bridges
24
Public highway bridges in Oliver County
County profile · official public datasets
Oliver County, ND
24 public highway bridges tracked in the FHWA National Bridge Inventory: 41.7% rated Good, 50% Fair, 8.3% Poor.
- 24
- Public bridges
- 41.7%
- Good condition
- 8.3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Oliver County posts a higher-than-median Poor-condition share among rated counties in the state across rated county bridge inventory.
- 27th
- of 53 on Poor share
- 8.3%
- Poor-condition share
- 24
- public highway bridges
- 1974
- 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.
Oliver County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Oliver County ranks #27 of 53 North Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.3%). Oliver County, North Dakota contains 24 public highway bridges. Roughly 41.7% are rated “Good,” 50% “Fair,” and 8.3% “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
41.7%
10 of 24 rated 7-9
Fair condition
50%
12 of 24 rated 5-6
Poor condition
8.3%
2 of 24 rated 4 or below
In-state Poor-share rank
#27 of 53
Among North Dakota counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 24 NBI-tracked bridges by lowest applicable component rating.
Good 41.7% (10)
Fair 50% (12)
Poor 8.3% (2)
Oliver County's Poor-condition bridges carry 985 vehicle crossings a day
That is 12.4% of the county's reported daily bridge traffic on 8.3% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 493 crossings a day against 269 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 24 of 24 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
41.7% of Oliver County's bridges have passed the 50-year mark
10 of the 24 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 41.7% 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 95.4% of the county's Poor-condition bridge traffic
ND HIGHWAY 200 over CREEK, built 1971, carries 940 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 2-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 985 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Oliver County's bridges were built
24 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1940s 1
1940–1949
1 bridges
- 1960s
1960–1969
4 bridges
- 1970s
1970–1979
7 bridges
- 1980s
1980–1989
8 bridges
- 1990s 3
1990–1999
3 bridges
What this shows Construction peaked in the 1980s, when 8 of the county's bridges still in the inventory were built, which is 33.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1974) matches the North Dakota average (1975).
How Oliver County compares with North Dakota's closest counties by inventory size
The 5 North Dakota counties nearest Oliver County in number of bridges, with their condition splits. Its 8.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1974 is in line with the group.
Showing the 5 closest of 52 North Dakota counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Eddy County | 27 | 59.3% | 29.6% | 11.1% | 1979 |
| Renville County | 24 | 25% | 66.7% | 8.3% | 1972 |
| Oliver County (this page) | 24 | 41.7% | 50% | 8.3% | 1974 |
| Nelson County | 23 | 34.8% | 47.8% | 17.4% | 1975 |
| Griggs County | 22 | 63.6% | 27.3% | 9.1% | 1974 |
| Sioux County | 22 | 59.1% | 36.4% | 4.5% | 1970 |
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 Oliver 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 Oliver County, both outside North Dakota so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside ND (24 bridges here).
- Meade County, KY · 24 bridges
- Robertson County, KY · 24 bridges
- Garfield County, NE · 24 bridges
- De Baca County, NM · 24 bridges
Similar average build year
Nearest mean year-built outside ND (1974 here).
- Knox County, TN · avg 1974 · 588 bridges
- Summit County, OH · avg 1974 · 563 bridges
- Onondaga County, NY · avg 1974 · 472 bridges
- Orange County, NY · avg 1974 · 472 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (12)
21st Street SW
FairOver: SQUARE BUTTE CREEK
1 WEST OF HANNOVER, Oliver, ND
Built 1984 Load: 15.0 t ADT: 200
ND HIGHWAY
FairOver: BR. SQUARE BUTTE CREEK
2 NORTH OF HANNOVER, Oliver, ND
Built 1948 Load: 18.0 t ADT: 560
21ST ST SW
FairOver: OTTER CREEK
8 WEST OF HANNOVER, Oliver, ND
Built 1960 Load: 19.1 t ADT: 90
28th Street SW
FairOver: CREEK
7 SOUTH 1 EAST HANNOVER, Oliver, ND
Built 1983 Load: 19.1 t ADT: 35
COUNTY HIGHWAY
FairOver: BAUKOL-NOONAN MINE ROAD
3 SOUTH 2 EAST OF CENTER, Oliver, ND
Built 1985 Load: 19.1 t ADT: 115
COUNTY HIGHWAY
FairOver: SQUARE BUTTE CREEK
8 WEST 3 SOUTH OF PRICE, Oliver, ND
Built 1960 Load: 19.1 t ADT: 110
COUNTY HIGHWAY
FairOver: SQUARE BUTTE CREEK
6 WEST 5 SOUTH OF PRICE, Oliver, ND
Built 1978 Load: 28.0 t ADT: 27
14th Street SW
FairOver: BRADY CREEK
7 WEST 7 NORTH HANNOVER, Oliver, ND
Built 1919 Load: 29.9 t ADT: 15
ND HIGHWAY 200
FairOver: MISSOURI RIVER
1 WEST OF US 83, Oliver, ND
Built 1971 Load: 34.2 t ADT: 1,430
19th St SW
FairOver: BRUSH CREEK
16 WEST 2 NORTH HANNOVER, Oliver, ND
Built 1960 Load: 34.6 t ADT: 25
ND HIGHWAY 48
FairOver: CREEK
7 NORTH OF CENTER, Oliver, ND
Built 1970 Load: 38.2 t ADT: 530
ND HIGHWAY 200
FairOver: CREEK
6 EAST OF ND 48, Oliver, ND
Built 1970 Load: 47.4 t ADT: 1,140
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.