Total bridges
3
Public highway bridges in Los Alamos County
County profile · official public datasets
3 public highway bridges tracked in the FHWA National Bridge Inventory: 33.3% rated Good, 33.3% Fair, 33.3% Poor.
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
Share of 3 NBI-tracked bridges by lowest applicable component rating.
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.
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.
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.
3 bridges with a recorded construction year, grouped by decade
1950–1959
2 bridges
2010–2019
1 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).
Over: Glen Canyon
Jct. Arkansas/Glen Canyon, Los Alamos, NM
Over: UNNAMED WATERWAY
NM 4 MM 61.6, Los Alamos, NM
Over: Omega Road West Road
JCT.NM501 and Omega Road, Los Alamos, NM
Read our methodology - how this data is sourced, computed, and verified.
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.