County profile · official public datasets

Mohave County, AZ

641 public highway bridges tracked in the FHWA National Bridge Inventory: 71.6% rated Good, 27.8% Fair, 0.6% Poor.

641
Public bridges: 71.6%
Good condition: 0.6%
Poor condition

The verdict

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

Mohave County posts a top-quartile lowest Poor-condition share among rated counties in the state across large county bridge inventory.

Top 20%
lowest Poor share in state: 0.6%
Poor-condition share: 641
public highway bridges: 1976
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.

Mohave County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Mohave County ranks #3 of 15 Arizona counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0.6%). Mohave County, Arizona contains 641 public highway bridges. Roughly 71.6% are rated “Good,” 27.8% “Fair,” and 0.6% “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

641

Public highway bridges in Mohave County

Good condition

71.6%

459 of 641 rated 7-9

Fair condition

27.8%

178 of 641 rated 5-6

Poor condition

0.6%

4 of 641 rated 4 or below

In-state Poor-share rank

#3 of 15

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

Condition distribution

Share of 641 NBI-tracked bridges by lowest applicable component rating.

Good

71.6% (459)

Fair

27.8% (178)

Poor

0.6% (4)

Mohave County's Poor-condition bridges carry 91,317 vehicle crossings a day

That is 1.6% of the county's reported daily bridge traffic on 0.6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 22,829 crossings a day against 9,289 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 641 of 641 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

51.8% of Mohave County's bridges have passed the 50-year mark

332 of the 641 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 71.6% 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 35.3% of the county's Poor-condition bridge traffic

I 15 over Virgin River, built 1967, carries 32,192 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 4-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 91,317 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

3
1930s

67
1940s

11
1950s

55
1960s

149
1970s

96
1980s

53
1990s

79
2000s

89
2010s

34
2020s

4

What this shows Construction peaked in the 1960s, when 149 of the county's bridges still in the inventory were built, which is 23.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1976) matches the Arizona average (1977).

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

The 5 Arizona counties nearest Mohave County in number of bridges, with their condition splits. Its 0.6% Poor share is the 2nd-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1966 is 10 years newer.

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

Bridge inventory size and condition shares for Mohave County and the 5 Arizona counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Pinal County	716	63.5%	35.5%	1%	1973
Mohave County (this page)	641	71.6%	27.8%	0.6%	1976
Yavapai County	543	63.2%	36.3%	0.6%	1970
Cochise County	501	55.3%	42.5%	2.2%	1956
Coconino County	405	51.9%	46.9%	1.2%	1969
La Paz County	306	64.1%	32.4%	3.6%	1961

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 Mohave 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 Mohave County, both outside Arizona so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside AZ (641 bridges here).

San Joaquin County, CA · 644 bridges
Spartanburg County, SC · 638 bridges
Greenville County, SC · 635 bridges
Will County, IL · 649 bridges

Similar average build year

Nearest mean year-built outside AZ (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges
New Castle County, DE · avg 1976 · 527 bridges

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

All 641 Good 459 Fair 178 Poor 4

Good-condition bridges (459)

Sort:

Mohave County Bridge Snapshot

Condition distribution

Mohave County's Poor-condition bridges carry 91,317 vehicle crossings a day

51.8% of Mohave County's bridges have passed the 50-year mark

One structure carries 35.3% of the county's Poor-condition bridge traffic

How Mohave 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

Good-condition bridges (459)

SR 66

SR 66

IRR SR 66

IRR SR 66

IRR SR 66

IRR SR 66

IRR SR 66

US 93; SB

US 93

US 93

US 93

US 93

US 93

US 93

US 93

IRR SR 389

US 93 Access Rd

Scenic Boulevard

County Hwy 91

I-40 EB

Port-of-Entry Ramp

US 93

US 93

US 93

US 93

I 15

US 93

US 93 SB

I 40; EB

I-40 EB

I-40 WB

US 93

US 93

US 93

US 93

US 93

IRR SR 389

I 15; NB

I 15; SB

I 40; EB & WB

SR 95

I 15

SR 95

Griffith Rd

I-40 WB

I-40 EB

SR 68 EB

SR 68 WB

US 93

I 40; WB

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