Total bridges
182
Public highway bridges in Logan County
County profile · official public datasets
Logan County, CO
182 public highway bridges tracked in the FHWA National Bridge Inventory: 36.8% rated Good, 54.4% Fair, 8.8% Poor.
- 182
- Public bridges
- 36.8%
- Good condition
- 8.8%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Logan County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 58th
- of 64 on Poor share
- 8.8%
- Poor-condition share
- 182
- public highway bridges
- 1984
- 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.
Logan County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Logan County ranks #58 of 64 Colorado counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.8%). Logan County, Colorado contains 182 public highway bridges. Roughly 36.8% are rated “Good,” 54.4% “Fair,” and 8.8% “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
36.8%
67 of 182 rated 7-9
Fair condition
54.4%
99 of 182 rated 5-6
Poor condition
8.8%
16 of 182 rated 4 or below
In-state Poor-share rank
#58 of 64
Among Colorado counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 182 NBI-tracked bridges by lowest applicable component rating.
Good 36.8% (67)
Fair 54.4% (99)
Poor 8.8% (16)
Logan County's Poor-condition bridges carry 8,273 vehicle crossings a day
That is 3.6% of the county's reported daily bridge traffic on 8.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 552 crossings a day against 1,250 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 179 of 182 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
30.2% of Logan County's bridges have passed the 50-year mark
55 of the 182 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 36.8% 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 66.5% of the county's Poor-condition bridge traffic
I 76 ML EBND over TWENTY TWO SLOUGH, built 1964, carries 5,500 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 16-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 8,273 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Logan County's bridges were built
182 bridges with a recorded construction year, grouped by decade
- 1920s 1
1920–1929
1 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 11
1940–1949
11 bridges
- 1950s 8
1950–1959
8 bridges
- 1960s
1960–1969
27 bridges
- 1970s 6
1970–1979
6 bridges
- 1980s
1980–1989
30 bridges
- 1990s
1990–1999
56 bridges
- 2000s
2000–2009
27 bridges
- 2010s 10
2010–2019
10 bridges
- 2020s 1
2020–2029
1 bridges
What this shows Construction peaked in the 1990s, when 56 of the county's bridges still in the inventory were built, which is 30.8% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1984) matches the Colorado average (1982).
How Logan County compares with Colorado's closest counties by inventory size
The 5 Colorado counties nearest Logan County in number of bridges, with their condition splits. Its 8.8% Poor share is the 4th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1978 is 6 years newer.
Showing the 5 closest of 63 Colorado counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Las Animas County | 207 | 26.1% | 59.9% | 14% | 1968 |
| Otero County | 195 | 24.6% | 65.1% | 10.3% | 1973 |
| Morgan County | 192 | 47.9% | 49.5% | 2.6% | 1986 |
| Logan County (this page) | 182 | 36.8% | 54.4% | 8.8% | 1984 |
| Eagle County | 174 | 39.7% | 55.2% | 5.2% | 1984 |
| Garfield County | 167 | 34.7% | 64.1% | 1.2% | 1980 |
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 Logan 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 Logan County, both outside Colorado so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside CO (182 bridges here).
- Ida County, IA · 182 bridges
- Wright County, IA · 182 bridges
- Pulaski County, KY · 182 bridges
- Jackson County, MN · 182 bridges
Similar average build year
Nearest mean year-built outside CO (1984 here).
- Hennepin County, MN · avg 1984 · 936 bridges
- Duval County, FL · avg 1984 · 831 bridges
- Bell County, TX · avg 1984 · 660 bridges
- Steuben County, NY · avg 1984 · 627 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (16)
County Road 59
PoorOver: N. Sterling Outlet Canal
0.3 Mi N of Co Rd 58, Logan, CO
Built 1940 Load: 1.4 t ADT: 6
County Road 71
PoorOver: Spring Canyon Creek
0.9 Mi N of Co Rd 64, Logan, CO
Built 1940 Load: 5.7 t ADT: 126
County Road 83
PoorOver: Duck Creek
0.9 Mi N of Co Rd 64, Logan, CO
Built 1993 Load: 6.6 t ADT: 3
County Road 91
PoorOver: Trib.N.Fork Frenchman Ck
0.8 Mi N of Co Rd 22, Logan, CO
Built 1940 Load: 8.7 t ADT: 65
County Road 26
PoorOver: N. Sterling Inlet Canal
0.1 Mi East of Co Rd 29, Logan, CO
Built 1940 Load: 9.0 t ADT: 73
County Road 52
PoorOver: N. Sterling Outlet Canal
1.8 Mi E of Co Rd 45, Logan, CO
Built 1985 Load: 11.1 t ADT: 33
County Road 93
PoorOver: South Platte River
1.1 Mi N of I-76, Logan, CO
Built 1984 Load: 17.6 t ADT: 62
County Road 48
PoorOver: N. Sterling Outlet Canal
0.8 Mi E of Co Rd 37, Logan, CO
Built 1985 Load: 19.9 t ADT: 43
US 6 ML EBND
PoorOver: STERLING CANAL NO 1
4.7 MI NE OF JCT SH 63, Logan, CO
Built 1941 Load: 24.5 t ADT: 2,150
CR 30.7 Vansway Dr
PoorOver: Sterling No 1 Ditch
0.2 Mi W of Co Rd 39, Logan, CO
Built 1960 Load: 24.5 t ADT: 104
County Road 50
PoorOver: N. Sterling Outlet Canal
Intersection w/ Co Rd 43, Logan, CO
Built 1982 Load: 26.8 t ADT: 47
I 76 ML EBND
PoorOver: TWENTY TWO SLOUGH
14 MI S.W. OF STERLING EX, Logan, CO
Built 1964 Load: 30.2 t ADT: 5,500
County Road 52
PoorOver: N. Sterling Outlet Canal
0.4 Mi E of Co Rd 45, Logan, CO
Built 1985 Load: 32.3 t ADT: 7
County Road 56.3
PoorOver: Harmony No2 Return Canal
0.4 Mi W of Co Rd 77, Logan, CO
Built 1930 Load: 32.7 t
County Road 66
PoorOver: Duck Creek
0.9 Mi E of Co Rd 81, Logan, CO
Built 1993 Load: 60.7 t ADT: 44
County Road 70
PoorOver: McCracken Draw 2 Butte
1.1 Mi E of Co Rd 81, Logan, CO
Built 1989 Load: 99.9 t ADT: 10
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.