County profile · official public datasets

Maricopa County, AZ

2,847 public highway bridges tracked in the FHWA National Bridge Inventory: 68.9% rated Good, 30.9% Fair, 0.1% Poor.

2,847
Public bridges: 68.9%
Good condition: 0.1%
Poor condition

The verdict

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

Maricopa County pairs a top-10% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 7%
lowest Poor share in state: 0.1%
Poor-condition share: 2,847
public highway bridges: 1990
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.

Maricopa County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Maricopa County ranks #1 of 15 Arizona counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0.1%). Maricopa County, Arizona contains 2,847 public highway bridges. Roughly 68.9% are rated “Good,” 30.9% “Fair,” and 0.1% “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

2,847

Public highway bridges in Maricopa County

Good condition

68.9%

1,962 of 2,847 rated 7-9

Fair condition

30.9%

881 of 2,847 rated 5-6

Poor condition

0.1%

4 of 2,847 rated 4 or below

In-state Poor-share rank

#1 of 15

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

Condition distribution

Share of 2,847 NBI-tracked bridges by lowest applicable component rating.

Good

68.9% (1,962)

Fair

30.9% (881)

Poor

0.1% (4)

Maricopa County's Poor-condition bridges carry 45,254 vehicle crossings a day

That is 0.1% of the county's reported daily bridge traffic on 0.1% of its bridges: Poor-condition structures carry the same share of traffic than their share of the inventory. Each Poor bridge averages 11,314 crossings a day against 23,107 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 2,844 of 2,847 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

20.3% of Maricopa County's bridges have passed the 50-year mark

578 of the 2,847 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 68.9% 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 83.1% of the county's Poor-condition bridge traffic

Shea Boulevard over Indian Bend Wash, built 1976, carries 37,601 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 45,254 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

1
1920s

16
1930s

58
1940s

25
1950s

110
1960s

218
1970s

305
1980s

542
1990s

585
2000s

657
2010s

280
2020s

49

What this shows Construction peaked in the 2000s, when 657 of the county's bridges still in the inventory were built, which is 23.1% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1990, 13 years newer than the Arizona average of 1977.

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

The 5 Arizona counties nearest Maricopa County in number of bridges, with their condition splits. Its 0.1% Poor share is the 1st-lowest of these 6. Its average build year of 1990 against a peer-group mean of 1971 is 19 years newer.

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

Bridge inventory size and condition shares for Maricopa County and the 5 Arizona counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Maricopa County (this page)	2,847	68.9%	30.9%	0.1%	1990
Pima County	1,150	68.2%	31%	0.8%	1979
Pinal County	716	63.5%	35.5%	1%	1973
Mohave County	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

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

Similar inventory size

Nearest county inventories outside AZ (2,847 bridges here).

Tarrant County, TX · 2,617 bridges
Dallas County, TX · 3,230 bridges
Bexar County, TX · 2,342 bridges
Los Angeles County, CA · 3,547 bridges

Similar average build year

Nearest mean year-built outside AZ (1990 here).

Fairfax County, VA · avg 1990 · 751 bridges
Guilford County, NC · avg 1990 · 736 bridges
Brazoria County, TX · avg 1990 · 618 bridges

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

All 2,847 Good 1,962 Fair 881 Poor 4

Good-condition bridges (1,962)

Sort:

Maricopa County Bridge Snapshot

Condition distribution

Maricopa County's Poor-condition bridges carry 45,254 vehicle crossings a day

20.3% of Maricopa County's bridges have passed the 50-year mark

One structure carries 83.1% of the county's Poor-condition bridge traffic

How Maricopa 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 (1,962)

SR 51

SR 51

SR 51

I 10; WB

I 10; EB

I 10; EB

SR 85; Ramp C

I 10

US 60

EB 10-SB 17 Ramp

Adams St

I 10; WB

51st Avenue

I 10 EB

Palo Verde Road

23rd Avenue

SL 202 E Papago

L 202 (E Papago)

L 202 (E Papago)

SR 143 (Hohokam)

SR 143 (Hohokam)

SR Loop 101

SL 202 (Red Mtn)

Ramp 101SB / 60WB

Ramp 202W to 101N

US 60 EB

SR 87

SR 51

SR 51

SR 101L WB

SR 101L SB

SR 85

Loop 101 NB

Williams Gatewy Fr

Ramp A

Gilbert Road

Thomas Road EB

Thomas Road WB

51st Avenue

101L WB

SR 85

67th Ave

Guadalupe Road

I-10

I-10/HOV Lanes

Val Vista Drive

202L

SR 202L

SR 202L

SR202/Red Mt

Related