Total bridges
175
Public highway bridges in San Miguel County
County profile · official public datasets
San Miguel County, NM
175 public highway bridges tracked in the FHWA National Bridge Inventory: 41.1% rated Good, 50.9% Fair, 8% Poor.
- 175
- Public bridges
- 41.1%
- Good condition
- 8%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
San Miguel County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 28th
- of 32 on Poor share
- 8%
- Poor-condition share
- 175
- public highway bridges
- 1972
- 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.
San Miguel County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, San Miguel County ranks #28 of 32 New Mexico counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8%). San Miguel County, New Mexico contains 175 public highway bridges. Roughly 41.1% are rated “Good,” 50.9% “Fair,” and 8% “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.
Good condition
41.1%
72 of 175 rated 7-9
Fair condition
50.9%
89 of 175 rated 5-6
Poor condition
8%
14 of 175 rated 4 or below
In-state Poor-share rank
#28 of 32
Among New Mexico counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 175 NBI-tracked bridges by lowest applicable component rating.
Good 41.1% (72)
Fair 50.9% (89)
Poor 8% (14)
San Miguel County's Poor-condition bridges carry 6,735 vehicle crossings a day
That is 1.5% of the county's reported daily bridge traffic on 8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 481 crossings a day against 2,274 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 175 of 175 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
52% of San Miguel County's bridges have passed the 50-year mark
91 of the 175 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 41.1% 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 35.5% of the county's Poor-condition bridge traffic
US-84 over I-25 NBL/SBL, built 1966, carries 2,388 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 14-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 6,735 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When San Miguel County's bridges were built
175 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 3
1910–1919
3 bridges
- 1920s 1
1920–1929
1 bridges
- 1930s 7
1930–1939
7 bridges
- 1940s
1940–1949
20 bridges
- 1950s
1950–1959
16 bridges
- 1960s
1960–1969
31 bridges
- 1970s
1970–1979
24 bridges
- 1980s
1980–1989
40 bridges
- 1990s 11
1990–1999
11 bridges
- 2000s 11
2000–2009
11 bridges
- 2010s 9
2010–2019
9 bridges
- 2020s 1
2020–2029
1 bridges
What this shows Construction peaked in the 1980s, when 40 of the county's bridges still in the inventory were built, which is 22.9% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1972) matches the New Mexico average (1973).
How San Miguel County compares with New Mexico's closest counties by inventory size
The 5 New Mexico counties nearest San Miguel County in number of bridges, with their condition splits. Its 8% Poor share is the 6th-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1972 is in line with the group.
Showing the 5 closest of 31 New Mexico counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Socorro County | 188 | 16.5% | 76.1% | 7.4% | 1961 |
| Sandoval County | 182 | 40.7% | 54.4% | 4.9% | 1979 |
| San Miguel County (this page) | 175 | 41.1% | 50.9% | 8% | 1972 |
| San Juan County | 174 | 36.8% | 56.9% | 6.3% | 1977 |
| Rio Arriba County | 160 | 47.5% | 46.3% | 6.3% | 1973 |
| Colfax County | 140 | 37.9% | 57.1% | 5% | 1969 |
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 San Miguel 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 San Miguel County, both outside New Mexico so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside NM (175 bridges here).
- Smith County, MS · 175 bridges
- Warren County, MS · 175 bridges
- Hamilton County, NE · 175 bridges
- Madison County, NY · 175 bridges
Similar average build year
Nearest mean year-built outside NM (1972 here).
- Santa Clara County, CA · avg 1972 · 964 bridges
- Madison County, AL · avg 1972 · 710 bridges
- Kern County, CA · avg 1972 · 668 bridges
- York County, PA · avg 1972 · 569 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (89)
47-0C23
FairOver: PECOS ARROYO
1.8 MI N OF I-25 FRNTG RD, San Miguel, NM
Built 1976 Load: 32.4 t ADT: 198
NM-250
FairOver: UNNAMED WATERWAY
0.4 MI NE OF I-25, San Miguel, NM
Built 1982 Load: 32.4 t ADT: 483
NM-250
FairOver: UNNAMED WATERWAY
0.6 MI NE OF I-25, San Miguel, NM
Built 1982 Load: 32.4 t ADT: 483
47-Z024
FairOver: UNNAMED WATERWAY
0.15 M SE OF I-25 FRTG RD, San Miguel, NM
Built 1983 Load: 32.4 t ADT: 198
NM-63
FairOver: PECOS RIVER @ COWELS
19.1 MI N OF NM-223/PECOS, San Miguel, NM
Built 1993 Load: 32.4 t ADT: 198
NM-518
FairOver: UNNAMED WATERWAY
6.4 Mi N LOOP-15-/Vegas, San Miguel, NM
Built 2000 Load: 32.4 t ADT: 3,490
NM-104
FairOver: TRINCHERA CREEK
7.7 NW Loop-36/Tucumcari, San Miguel, NM
Built 2002 Load: 32.4 t ADT: 229
I-25 NBL
FairOver: Tecolote Creek
4.6 Mi S US-84/Romerovill, San Miguel, NM
Built 1966 Load: 32.7 t ADT: 9,714
I-25 SBL
FairOver: Tecolote Creek
4.6 Mi N US-84/Romerovill, San Miguel, NM
Built 1966 Load: 32.7 t ADT: 9,714
I-25 NBL
FairOver: BNSF RAILROAD
1.7 MI S OF NM-104, San Miguel, NM
Built 1982 Load: 32.7 t ADT: 9,083
IG-2345
FairOver: PECOS ARROYO
I-25/NM-104 INTERCHANGE, San Miguel, NM
Built 1982 Load: 32.7 t ADT: 333
IA-2345
FairOver: PECOS ARROYO
I-25/NM-104 INTERCHANGE, San Miguel, NM
Built 1982 Load: 32.7 t ADT: 1,515
I-25 NB
FairOver: NM-63
4.8 Mi N of Santa Fe C/L, San Miguel, NM
Built 1964 Load: 33.3 t ADT: 9,186
NM-65
FairOver: HILL SIDE
5.1 MI NW OF MILLS AVE, San Miguel, NM
Built 1990 Load: 33.4 t ADT: 76
I-25 SBL
FairOver: COUNTY RD-21
1.4 MI S OF JCT NM-104, San Miguel, NM
Built 1982 Load: 33.6 t ADT: 9,083
NM-283
FairOver: AGUA ZARCA CREEK
3.0 MI WEST OF JCT I-25, San Miguel, NM
Built 1979 Load: 34.3 t ADT: 422
NM-283
FairOver: AGUA ZARCA CREEK
2.1 MI WEST OF JCT I-25, San Miguel, NM
Built 1979 Load: 34.3 t ADT: 422
FR-2183
FairOver: PECOS ARROYO
0.3 MI S OF JCT NM-104, San Miguel, NM
Built 1981 Load: 34.3 t ADT: 234
NM-3
FairOver: PECOS RIVER
12.0 MI S OF I-25, San Miguel, NM
Built 1980 Load: 34.5 t ADT: 131
NM-283
FairOver: AGUA ZARCA CREEK
2.6 MI WEST OF JCT I-25, San Miguel, NM
Built 1979 Load: 34.9 t ADT: 422
NM-283
FairOver: AGUA ZARCA CREEK
1.3 MI WEST OF JCT I-25, San Miguel, NM
Built 1979 Load: 35.1 t ADT: 422
FR-2138
FairOver: I-25 NBLS/SBLS
1.7 M S OF S VEGAS INTRCH, San Miguel, NM
Built 1973 Load: 35.9 t ADT: 313
NM-518
FairOver: SAPELLO RIVER
0.2 MI S OF JCT NM-94, San Miguel, NM
Built 1978 Load: 36.4 t ADT: 3,490
47-B43B
FairOver: PECOS RIVER
1.8 MI N OF I-25 FRTG RD, San Miguel, NM
Built 1974 Load: 37.6 t ADT: 198
I-25 SBL
FairOver: PECOS ARROYO
1 M N OF N VEGAS INTERCHG, San Miguel, NM
Built 1982 Load: 37.9 t ADT: 7,494
I-25 NBL
FairOver: PECOS ARROYO
1 M N OF N VEGAS INTERCHG, San Miguel, NM
Built 1982 Load: 37.9 t ADT: 7,494
FR-2116
FairOver: BERNAL CREEK
6.9 MI N OF JCT NM-3, San Miguel, NM
Built 1941 Load: 38.9 t ADT: 239
FR-2116
FairOver: UNNAMED WATERWAY
1.9 MI N OF JCT NM-3, San Miguel, NM
Built 1941 Load: 38.9 t ADT: 239
NM-283
FairOver: TECOLOTE CREEK
13.7 MI W OF JCT I-25, San Miguel, NM
Built 1977 Load: 38.9 t ADT: 422
FDR 122
FairOver: HOLY GHOST CREEK
.02 MI N/O HOLY GHOST TR, San Miguel, NM
Built 1987 Load: 39.9 t ADT: 250
US-84
FairOver: BNSF RAILROAD
0.1 S OF I-25/ROMEROVILLE, San Miguel, NM
Built 1984 Load: 40.5 t ADT: 2,388
FDR 122
FairOver: HOLY GHOST CREEK
.03 MI W/O HOLY GHOST CG, San Miguel, NM
Built 1987 Load: 40.5 t ADT: 250
I-25 SBL
FairOver: NM-63
4.8 M N of Santa Fe, San Miguel, NM
Built 2009 Load: 40.7 t ADT: 9,186
I-25 NB
FairOver: NM-3
16.4 Mi S US-84/Romerovil, San Miguel, NM
Built 1966 Load: 44.3 t ADT: 8,884
I-25 SB
FairOver: NM-3
16.4 MI S US-84/Romerovil, San Miguel, NM
Built 1966 Load: 44.3 t ADT: 8,884
NM-63
FairOver: GLORIETA CREEK
2.5 m. S from Jct. NM-223, San Miguel, NM
Built 2004 Load: 44.9 t ADT: 912
NM-104
FairOver: GARITA CREEK
13.5 MI S OF NM-419, San Miguel, NM
Built 1995 Load: 45.2 t ADT: 171
I-25 NBL
FairOver: AGUA SARCA CREEK
1.1 M S OF S VEGAS INTRCH, San Miguel, NM
Built 1973 Load: 48.0 t ADT: 11,619
I-25 SBL
FairOver: AGUA SARCA CREEK
1.1 M S OF S VEGAS INTRCH, San Miguel, NM
Built 1973 Load: 48.0 t ADT: 11,619
Read our methodology - how this data is sourced, computed, and verified.
Related
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.