County profile · official public datasets

Cass County, ND

369 public highway bridges tracked in the FHWA National Bridge Inventory: 52% rated Good, 43.4% Fair, 4.6% Poor.

369
Public bridges: 52%
Good condition: 4.6%
Poor condition

The verdict

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

Cass 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 32%
lowest Poor share in state: 4.6%
Poor-condition share: 369
public highway bridges: 1987
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.

Cass County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Cass County ranks #17 of 53 North Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.6%). Cass County, North Dakota contains 369 public highway bridges. Roughly 52% are rated “Good,” 43.4% “Fair,” and 4.6% “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

369

Public highway bridges in Cass County

Good condition

52%

192 of 369 rated 7-9

Fair condition

43.4%

160 of 369 rated 5-6

Poor condition

4.6%

17 of 369 rated 4 or below

In-state Poor-share rank

#17 of 53

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

Condition distribution

Share of 369 NBI-tracked bridges by lowest applicable component rating.

Good

52% (192)

Fair

43.4% (160)

Poor

4.6% (17)

Cass County's Poor-condition bridges carry 9,396 vehicle crossings a day

That is 0.8% of the county's reported daily bridge traffic on 4.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 553 crossings a day against 2,834 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 369 of 369 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

36.3% of Cass County's bridges have passed the 50-year mark

134 of the 369 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% 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 86.9% of the county's Poor-condition bridge traffic

COUNTY HIGHWAY over SHEYENNE RIVER, built 1971, carries 8,162 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 17-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,396 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

10
1940s

12
1950s

47
1960s

40
1970s

37
1980s

30
1990s

44
2000s

57
2010s

62
2020s

30

What this shows Construction peaked in the 2010s, when 62 of the county's bridges still in the inventory were built, which is 16.8% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year is 1987, 12 years newer than the North Dakota average of 1975.

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

The 5 North Dakota counties nearest Cass County in number of bridges, with their condition splits. Its 4.6% Poor share is the 1st-lowest of these 6. Its average build year of 1987 against a peer-group mean of 1971 is 16 years newer.

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

Bridge inventory size and condition shares for Cass County and the 5 North Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Cass County (this page)	369	52%	43.4%	4.6%	1987
Grand Forks County	335	30.4%	57%	12.5%	1974
Morton County	272	42.3%	48.9%	8.8%	1971
Walsh County	257	30%	50.2%	19.8%	1969
Pembina County	204	22.5%	54.9%	22.5%	1969
Richland County	197	38.1%	48.7%	13.2%	1971

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

Similar inventory size

Nearest county inventories outside ND (369 bridges here).

Saline County, KS · 369 bridges
Suffolk County, NY · 369 bridges
Waukesha County, WI · 369 bridges
Collier County, FL · 370 bridges

Similar average build year

Nearest mean year-built outside ND (1987 here).

St. Louis County, MO · avg 1987 · 912 bridges
Ellis County, TX · avg 1987 · 691 bridges
St. Louis County, MN · avg 1987 · 663 bridges
Palm Beach County, FL · avg 1987 · 610 bridges

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

All 369 Good 192 Fair 160 Poor 17

Fair-condition bridges (160)

Sort:

Cass County Bridge Snapshot

Condition distribution

Cass County's Poor-condition bridges carry 9,396 vehicle crossings a day

36.3% of Cass County's bridges have passed the 50-year mark

One structure carries 86.9% of the county's Poor-condition bridge traffic

How Cass 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 (160)

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