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.

Total bridges

182

Public highway bridges in Logan County

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.

1920s

1
1930s

5
1940s

11
1950s

8
1960s

27
1970s

6
1980s

30
1990s

56
2000s

27
2010s

10
2020s

1

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.

Bridge inventory size and condition shares for Logan County and the 5 Colorado counties closest to it in inventory size
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.

All 182 Good 67 Fair 99 Poor 16

Good-condition bridges (67)

Sort:

Logan County Bridge Snapshot

Condition distribution

Logan County's Poor-condition bridges carry 8,273 vehicle crossings a day

30.2% of Logan County's bridges have passed the 50-year mark

One structure carries 66.5% of the county's Poor-condition bridge traffic

How Logan County compares with Colorado'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 (67)

SH 55 ML

County Road 55

US 138 ML

County Road 18

County Road 65

SH 55 ML

SH 55 ML

SH 55 ML

County Road 34

County Road 16.5

County Road 93

County Road 24

County Road 91

SH 6 ML

County Road 23

County Road 68

County Road 20

County Road 78

County Road 2.5

I 76 ML EBND

County Road 27

SH 63 ML

County Road 33

County Road 89

County Road 71

County Road 85

County Road 33.5

SH 138 ML

County Road 35

I 76 ML WBND

County Road 37

County Road 40

County Road 46

Platte Street

County Road 55

County Road 71

County Road 25

I 76 ML WBND

County Road 40

County road 54

County Road 24

County Road 59

I 76 ML EBND

County Road 62

County Road 48

County Road 48.5

County Road 62

I 76 ML WBND

I76 ML EBND

I 76 ML WBND

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