County profile · official public datasets

La Paz County, AZ

306 public highway bridges tracked in the FHWA National Bridge Inventory: 64.1% rated Good, 32.4% Fair, 3.6% Poor.

306
Public bridges: 64.1%
Good condition: 3.6%
Poor condition

The verdict

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

La Paz County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

12th
of 15 on Poor share: 3.6%
Poor-condition share: 306
public highway bridges: 1961
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.

La Paz County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, La Paz County ranks #12 of 15 Arizona counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.6%). La Paz County, Arizona contains 306 public highway bridges. Roughly 64.1% are rated “Good,” 32.4% “Fair,” and 3.6% “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

306

Public highway bridges in La Paz County

Good condition

64.1%

196 of 306 rated 7-9

Fair condition

32.4%

99 of 306 rated 5-6

Poor condition

3.6%

11 of 306 rated 4 or below

In-state Poor-share rank

#12 of 15

Among Arizona counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 306 NBI-tracked bridges by lowest applicable component rating.

Good

64.1% (196)

Fair

32.4% (99)

Poor

3.6% (11)

La Paz County's Poor-condition bridges carry 6,403 vehicle crossings a day

That is 0.3% of the county's reported daily bridge traffic on 3.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 582 crossings a day against 8,997 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 306 of 306 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

84% of La Paz County's bridges have passed the 50-year mark

257 of the 306 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 64.1% 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 46.9% of the county's Poor-condition bridge traffic

IRR BIA RTE 1 over MAIN DRAIN, built 1962, carries 3,000 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 6,403 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

67
1940s

6
1950s

34
1960s

121
1970s

36
1980s

29
1990s

1
2000s

9
2010s

2
2020s

1

What this shows Construction peaked in the 1960s, when 121 of the county's bridges still in the inventory were built, which is 39.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1961, 16 years older than the Arizona average of 1977.

How La Paz County compares with Arizona's closest counties by inventory size

The 5 Arizona counties nearest La Paz County in number of bridges, with their condition splits. Its 3.6% Poor share is the 5th-lowest of these 6. Its average build year of 1961 against a peer-group mean of 1972 is 11 years older.

Showing the 5 closest of 14 Arizona counties eligible for comparison.

Bridge inventory size and condition shares for La Paz County and the 5 Arizona counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Coconino County	405	51.9%	46.9%	1.2%	1969
La Paz County (this page)	306	64.1%	32.4%	3.6%	1961
Navajo County	277	52.7%	45.1%	2.2%	1972
Yuma County	262	50.4%	47.7%	1.9%	1973
Apache County	259	48.3%	45.9%	5.8%	1973
Gila County	259	60.2%	37.5%	2.3%	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 La Paz 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 La Paz County, both outside Arizona so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside AZ (306 bridges here).

Adair County, IA · 306 bridges
Greene County, PA · 306 bridges
Greene County, TN · 306 bridges
Grant County, WA · 306 bridges

Similar average build year

Nearest mean year-built outside AZ (1961 here).

Westchester County, NY · avg 1961 · 774 bridges
Tehama County, CA · avg 1961 · 450 bridges
Berkshire County, MA · avg 1961 · 450 bridges
Schuylkill County, PA · avg 1961 · 368 bridges

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

All 306 Good 196 Fair 99 Poor 11

All bridges (306)

Sort:

La Paz County Bridge Snapshot

Condition distribution

La Paz County's Poor-condition bridges carry 6,403 vehicle crossings a day

84% of La Paz County's bridges have passed the 50-year mark

One structure carries 46.9% of the county's Poor-condition bridge traffic

How La Paz County compares with Arizona's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (306)

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SR 95

IRR SR 95

IRR BIA RTE 60

IRR BIA RTE 1

IRR BIA RTE 38

IRR BIA RTE 44

IRR BIA RTE 56

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