County profile · official public datasets

Harris County, TX

4,029 public highway bridges tracked in the FHWA National Bridge Inventory: 50.7% rated Good, 48.7% Fair, 0.6% Poor.

4,029
Public bridges: 50.7%
Good condition: 0.6%
Poor condition

The verdict

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

Harris 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 43%
lowest Poor share in state: 0.6%
Poor-condition share: 4,029
public highway bridges: 1989
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.

Harris County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Harris County ranks #106 of 247 Texas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0.6%). Harris County, Texas contains 4,029 public highway bridges. Roughly 50.7% are rated “Good,” 48.7% “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

4,029

Public highway bridges in Harris County

Good condition

50.7%

2,042 of 4,029 rated 7-9

Fair condition

48.7%

1,963 of 4,029 rated 5-6

Poor condition

0.6%

24 of 4,029 rated 4 or below

In-state Poor-share rank

#106 of 247

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

Condition distribution

Share of 4,029 NBI-tracked bridges by lowest applicable component rating.

Good

50.7% (2,042)

Fair

48.7% (1,963)

Poor

0.6% (24)

Harris County's Poor-condition bridges carry 472,127 vehicle crossings a day

That is 0.4% of the county's reported daily bridge traffic on 0.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 19,672 crossings a day against 26,874 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 4,029 of 4,029 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

22.1% of Harris County's bridges have passed the 50-year mark

892 of the 4,029 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 50.7% 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 24.6% of the county's Poor-condition bridge traffic

IH 45 NB over CROSSTIMBERS ST, built 1960, carries 116,204 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 24-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 472,127 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

3
1920s

9
1930s

12
1940s

30
1950s

114
1960s

475
1970s

533
1980s

816
1990s

810
2000s

579
2010s

519
2020s

129

What this shows Construction peaked in the 1980s, when 816 of the county's bridges still in the inventory were built, which is 20.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1989, 9 years newer than the Texas average of 1980.

How Harris County compares with Texas's closest counties by inventory size

The 5 Texas counties nearest Harris County in number of bridges, with their condition splits. Its 0.6% Poor share is the 5th-lowest of these 6. Its average build year of 1989 against a peer-group mean of 1988 is in line with the group.

Showing the 5 closest of 246 Texas counties eligible for comparison.

Bridge inventory size and condition shares for Harris County and the 5 Texas counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Harris County (this page)	4,029	50.7%	48.7%	0.6%	1989
Dallas County	3,230	42.5%	56.4%	1%	1983
Tarrant County	2,617	58.2%	41.4%	0.4%	1990
Bexar County	2,342	55%	44.7%	0.3%	1983
Travis County	1,544	63.9%	35.9%	0.2%	1988
Williamson County	1,170	67.4%	32.2%	0.3%	1995

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

Similar inventory size

Nearest county inventories outside TX (4,029 bridges here).

Los Angeles County, CA · 3,547 bridges
Maricopa County, AZ · 2,847 bridges
Cook County, IL · 1,721 bridges
San Diego County, CA · 1,632 bridges

Similar average build year

Nearest mean year-built outside TX (1989 here).

Mecklenburg County, NC · avg 1989 · 746 bridges
Buffalo County, NE · avg 1989 · 459 bridges
Dubuque County, IA · avg 1989 · 346 bridges
Vernon County, LA · avg 1989 · 341 bridges

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

All 4,029 Good 2,042 Fair 1,963 Poor 24

Good-condition bridges (2,042)

Sort:

Harris County Bridge Snapshot

Condition distribution

Harris County's Poor-condition bridges carry 472,127 vehicle crossings a day

22.1% of Harris County's bridges have passed the 50-year mark

One structure carries 24.6% of the county's Poor-condition bridge traffic

How Harris County compares with Texas'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 (2,042)

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