County profile · official public datasets

Douglas County, CO

263 public highway bridges tracked in the FHWA National Bridge Inventory: 57.8% rated Good, 39.9% Fair, 2.3% Poor.

263
Public bridges: 57.8%
Good condition: 2.3%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Douglas County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 28%
lowest Poor share in state: 2.3%
Poor-condition share: 263
public highway bridges: 1996
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.

Douglas County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Douglas County ranks #18 of 64 Colorado counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.3%). Douglas County, Colorado contains 263 public highway bridges. Roughly 57.8% are rated “Good,” 39.9% “Fair,” and 2.3% “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.

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

263

Public highway bridges in Douglas County

Good condition

57.8%

152 of 263 rated 7-9

Fair condition

39.9%

105 of 263 rated 5-6

Poor condition

2.3%

6 of 263 rated 4 or below

In-state Poor-share rank

#18 of 64

Among Colorado counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 263 NBI-tracked bridges by lowest applicable component rating.

Good

57.8% (152)

Fair

39.9% (105)

Poor

2.3% (6)

Douglas County's Poor-condition bridges carry 32,635 vehicle crossings a day

That is 0.6% of the county's reported daily bridge traffic on 2.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,439 crossings a day against 20,325 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 261 of 263 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

9.1% of Douglas County's bridges have passed the 50-year mark

24 of the 263 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 57.8% 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 45.8% of the county's Poor-condition bridge traffic

PLUM CREEK PKWY over SELLARS GULCH, built 1987, carries 14,950 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 6-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 32,635 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

1
1940s

2
1950s

2
1960s

15
1970s

8
1980s

60
1990s

62
2000s

52
2010s

41
2020s

20

What this shows Construction peaked in the 1990s, when 62 of the county's bridges still in the inventory were built, which is 23.6% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1996, 14 years newer than the Colorado average of 1982.

How Douglas County compares with Colorado's closest counties by inventory size

The 5 Colorado counties nearest Douglas County in number of bridges, with their condition splits. Its 2.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1996 against a peer-group mean of 1976 is 20 years newer.

Showing the 5 closest of 63 Colorado counties eligible for comparison.

Bridge inventory size and condition shares for Douglas County and the 5 Colorado counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Mesa County	319	35.1%	63.3%	1.6%	1981
Boulder County	311	34.4%	63.3%	2.3%	1987
Pueblo County	264	29.5%	65.9%	4.5%	1973
Douglas County (this page)	263	57.8%	39.9%	2.3%	1996
Las Animas County	207	26.1%	59.9%	14%	1968
Otero County	195	24.6%	65.1%	10.3%	1973

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 Douglas 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 Douglas County, both outside Colorado so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside CO (263 bridges here).

Bingham County, ID · 263 bridges
Guthrie County, IA · 263 bridges
Henry County, MO · 263 bridges
Sequoyah County, OK · 263 bridges

Similar average build year

Nearest mean year-built outside CO (1996 here).

Clark County, NV · avg 1996 · 1,141 bridges
Hamilton County, IN · avg 1996 · 454 bridges
Hays County, TX · avg 1996 · 272 bridges
Jackson County, MS · avg 1996 · 268 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 263 Good 152 Fair 105 Poor 6

Good-condition bridges (152)

Sort:

Douglas County Bridge Snapshot

Condition distribution

Douglas County's Poor-condition bridges carry 32,635 vehicle crossings a day

9.1% of Douglas County's bridges have passed the 50-year mark

One structure carries 45.8% of the county's Poor-condition bridge traffic

How Douglas 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 (152)

E-470 SB

SH 83 ML

SANTA FE DR.

WATERTON ROAD

EB MEADOWS PRKY

WB MEADOWS PRKY

SH 83 ML

CROSS CANYON TRL

E-470 EB

E-470 WB

LIGGETT ROAD

JORDAN ROAD

CANYONSIDE BLVD

SH 470 ML EBND

SH 470 ML WBND

SKYGAZER STREET

EB RIDGEGATE PKWY

I 25 NBND RAMP

SH 470 ML WBND

SH 470 ML EBND

LUCENT BLVD

E-470 WB

I 25 ML NBND

CHAMBERS RD NB

HAYSTACK ROAD

WESTBRIDGE DRIVE

FRONT ST

SH 470 ML EBND

SH 470 ML WBND

SH 470 ML EBND

WATERTON ROAD

WATERTON ROAD

SH 470 ML WBND

Castle Rock Pkwy

E-470 NB

US 85 TO C470 RAMP

US 85 ML

EB COTTONWOOD DR

CASTLE OAK DRIVE

PLUM CREEK PARKWAY

TIMBER MILL PKWY

N MEADOWS PARKWAY

WATERTON ROAD

RAMPART RANGE ROAD

Chambers Road NB

Chambers Road SB

SH 470 ML WBND

HESS ROAD WB

HESS ROAD EB

PINE LANE

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