County profile · official public datasets

Dunn County, ND

74 public highway bridges tracked in the FHWA National Bridge Inventory: 62.2% rated Good, 35.1% Fair, 2.7% Poor.

74
Public bridges: 62.2%
Good condition: 2.7%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Dunn County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 19%
lowest Poor share in state: 2.7%
Poor-condition share: 74
public highway bridges: 1988
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.

Dunn County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Dunn County ranks #10 of 53 North Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.7%). Dunn County, North Dakota contains 74 public highway bridges. Roughly 62.2% are rated “Good,” 35.1% “Fair,” and 2.7% “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.

Total bridges

Public highway bridges in Dunn County

Good condition

62.2%

46 of 74 rated 7-9

Fair condition

35.1%

26 of 74 rated 5-6

Poor condition

2.7%

2 of 74 rated 4 or below

In-state Poor-share rank

#10 of 53

Among North Dakota counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 74 NBI-tracked bridges by lowest applicable component rating.

Good

62.2% (46)

Fair

35.1% (26)

Poor

2.7% (2)

Dunn County's Poor-condition bridges carry 594 vehicle crossings a day

That is 1.8% of the county's reported daily bridge traffic on 2.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 297 crossings a day against 401 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 74 of 74 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

21.6% of Dunn County's bridges have passed the 50-year mark

16 of the 74 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 62.2% 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 96% of the county's Poor-condition bridge traffic

ND HIGHWAY 200 over CREEK, built 1957, carries 570 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 594 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

2
1940s

1
1950s

8
1960s

2
1970s

4
1980s

21
1990s

14
2000s

11
2010s

10
2020s

1

What this shows Construction peaked in the 1980s, when 21 of the county's bridges still in the inventory were built, which is 28.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1988, 13 years newer than the North Dakota average of 1975.

How Dunn County compares with North Dakota's closest counties by inventory size

The 5 North Dakota counties nearest Dunn County in number of bridges, with their condition splits. Its 2.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1988 against a peer-group mean of 1977 is 11 years newer.

Showing the 5 closest of 52 North Dakota counties eligible for comparison.

Bridge inventory size and condition shares for Dunn County and the 5 North Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Barnes County	79	55.7%	41.8%	2.5%	1978
Stutsman County	78	39.7%	53.8%	6.4%	1971
Dunn County (this page)	74	62.2%	35.1%	2.7%	1988
Mercer County	72	40.3%	54.2%	5.6%	1975
Bowman County	69	65.2%	31.9%	2.9%	1984
Emmons County	67	65.7%	31.3%	3%	1975

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 Dunn 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 Dunn County, both outside North Dakota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside ND (74 bridges here).

Clinch County, GA · 74 bridges
Decatur County, GA · 74 bridges
Hart County, GA · 74 bridges
Carlisle County, KY · 74 bridges

Similar average build year

Nearest mean year-built outside ND (1988 here).

Travis County, TX · avg 1988 · 1,544 bridges
Grant County, OK · avg 1988 · 476 bridges
Loudoun County, VA · avg 1988 · 442 bridges
Licking County, OH · avg 1988 · 439 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 74 Good 46 Fair 26 Poor 2

Fair-condition bridges (26)

Sort:

Dunn County Bridge Snapshot

Condition distribution

Dunn County's Poor-condition bridges carry 594 vehicle crossings a day

21.6% of Dunn County's bridges have passed the 50-year mark

One structure carries 96% of the county's Poor-condition bridge traffic

How Dunn County compares with North Dakota's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (26)

COUNTY HIGHWAY

25TH ST SW

104th Ave SW

ND HIGHWAY 22

79th Ave. SW

3RD ST SW

ND HIGHWAY 8

25th St SW

ND HIGHWAY 22

121ST AVE SW

ND HIGHWAY 200

116th AVE SW

6TH ST SW

82nd AVE SW

ND HIGHWAY 200

113TH AVE SW

ENTRANCE ROAD

IRRFB ND HIGHWAY 8

ND HIGHWAY 22

ND HIGHWAY 22

IRRFB ND HIWAY 22

93rd AVE SW

IRRFB ND HIWAY 22

ND HIGHWAY 8

ND HIGHWAY 200

ND HIGHWAY 22

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