County profile · official public datasets

Los Alamos County, NM

3 public highway bridges tracked in the FHWA National Bridge Inventory: 33.3% rated Good, 33.3% Fair, 33.3% Poor.

3
Public bridges
33.3%
Good condition
33.3%
Poor condition

Los Alamos County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Los Alamos County, New Mexico contains 3 public highway bridges. Roughly 33.3% are rated “Good,” 33.3% “Fair,” and 33.3% “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.

Los Alamos County is too small a bridge inventory (3 bridges) for a reliable Poor-share ordinal against New Mexico's other counties, but its bridges make up <0.1% of New Mexico's 4,035 total public highway bridges in the FHWA inventory.

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

3

Public highway bridges in Los Alamos County

Good condition

33.3%

1 of 3 rated 7-9

Fair condition

33.3%

1 of 3 rated 5-6

Poor condition

33.3%

1 of 3 rated 4 or below

Condition distribution

Share of 3 NBI-tracked bridges by lowest applicable component rating.

Good
33.3% (1)
Fair
33.3% (1)
Poor
33.3% (1)

Los Alamos County's Poor-condition bridges carry 8,118 vehicle crossings a day

That is 85.1% of the county's reported daily bridge traffic on 33.3% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 8,118 crossings a day against 976 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 3 of 3 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

66.7% of Los Alamos County's bridges have passed the 50-year mark

2 of the 3 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 33.3% 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 100% of the county's Poor-condition bridge traffic

NM501 over Omega Road West Road, built 1951, carries 8,118 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 1-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 8,118 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Los Alamos County's bridges were built

3 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 2 of the county's bridges still in the inventory were built, which is 66.7% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1972) matches the New Mexico average (1973).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

Good-condition bridges (1)

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.