County profile · official public datasets

Broomfield County, CO

66 public highway bridges tracked in the FHWA National Bridge Inventory: 42.4% rated Good, 56.1% Fair, 1.5% Poor.

66
Public bridges
42.4%
Good condition
1.5%
Poor condition

The verdict

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

Broomfield County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 14%
lowest Poor share in state
1.5%
Poor-condition share
66
public highway bridges
2000
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.

Broomfield County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Broomfield County ranks #9 of 64 Colorado counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.5%). Broomfield County, Colorado contains 66 public highway bridges. Roughly 42.4% are rated “Good,” 56.1% “Fair,” and 1.5% “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

66

Public highway bridges in Broomfield County

Good condition

42.4%

28 of 66 rated 7-9

Fair condition

56.1%

37 of 66 rated 5-6

Poor condition

1.5%

1 of 66 rated 4 or below

In-state Poor-share rank

#9 of 64

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

Condition distribution

Share of 66 NBI-tracked bridges by lowest applicable component rating.

Good
42.4% (28)
Fair
56.1% (37)
Poor
1.5% (1)

Broomfield County's Poor-condition bridges carry 25,000 vehicle crossings a day

That is 2.6% of the county's reported daily bridge traffic on 1.5% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 25,000 crossings a day against 17,076 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 66 of 66 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

4.5% of Broomfield County's bridges have passed the 50-year mark

3 of the 66 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 42.4% 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 100% of the county's Poor-condition bridge traffic

SH 121 ML SBND over US 287 ML RR SPUR, built 1972, carries 25,000 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 25,000 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Broomfield County's bridges were built

66 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 2000s, when 39 of the county's bridges still in the inventory were built, which is 59.1% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 2000, 18 years newer than the Colorado average of 1982.

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Colorado counties nearest Broomfield County in number of bridges, with their condition splits. Its 1.5% Poor share is the 1st-lowest of these 6. Its average build year of 2000 against a peer-group mean of 1981 is 19 years newer.

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

Bridge inventory size and condition shares for Broomfield County and the 5 Colorado counties closest to it in inventory size
County Bridges Poor
Bent County 68 2.9%
Broomfield County (this page) 66 1.5%
Delta County 64 3.1%
Sedgwick County 64 1.6%
Conejos County 62 14.5%
Pitkin County 62 3.2%

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

Similar inventory size

Nearest county inventories outside CO (66 bridges here).

Similar average build year

Nearest mean year-built outside CO (2000 here).

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

All 66 Good 28 Fair 37 Poor 1

Good-condition bridges (28)

Willow Run Pkwy

Good

Over: Local Drainage

Just S of Midway Blvd, Broomfield, CO

Built 1996 Load: 25.7 t ADT: 1,889

WB NWP Ramp

Good

Over: Rock Creek

5.70 MI FROM I-25, Broomfield, CO

Built 2002 Load: 26.9 t ADT: 2,300

Ramp H

Good

Over: I-25 and NWP

EB NWP ramp to NB I25, Broomfield, CO

Built 2003 Load: 31.8 t ADT: 1,500

Willow Run Pkwy

Good

Over: Local Drainage

200 FT W of ZUNI, Broomfield, CO

Built 1999 Load: 32.1 t ADT: 1,577

Interlocken Loop N

Good

Over: W. Flatiron Crossing Dr.

400 Ft N. of Interlocken, Broomfield, CO

Built 2000 Load: 32.7 t ADT: 6,228

Sheridan Boulevard

Good

Over: Local Drainage

0.6 Mi N of 120th Ave, Broomfield, CO

Built 1987 Load: 32.7 t ADT: 24,570

Zuni Street

Good

Over: Ped Undrpss/Plaster Rsrv

0.2 mi N of 136th Ave, Broomfield, CO

Built 2002 Load: 32.7 t ADT: 7,638

NWP WB

Good

Over: WB Dillon Road

5.59 MI FROM I-25, Broomfield, CO

Built 2002 Load: 32.7 t ADT: 12,000

US 36 ML

Good

Over: FLAT IRON CIRCLE EAST

NEAR FLATIRONS CROSSING, Broomfield, CO

Built 1999 Load: 32.8 t ADT: 62,000

Lowell Blvd SB

Good

Over: Lowell Channel

0.15 Mi S of SH7, Broomfield, CO

Built 2005 Load: 35.6 t ADT: 4,426

Ramp B

Good

Over: I-25 and NWP

I25 NB ramp to NWP WB, Broomfield, CO

Built 2003 Load: 35.7 t ADT: 820

SH 121 ML

Good

Over: US 36 ML

IN BROOMFIELD, Broomfield, CO

Built 2014 Load: 36.9 t ADT: 39,000

Broadlands Drive

Good

Over: Local Drainage

0.3 Mi N of 136th Ave, Broomfield, CO

Built 1997 Load: 37.1 t ADT: 1,465

Lowell Blvd NB

Good

Over: Lowell Channel

0.15 Mi S of SH7, Broomfield, CO

Built 2005 Load: 37.6 t ADT: 4,296

Interlocken Loop S

Good

Over: W. Flatiron Crossing

400 Ft N. of Interlocken, Broomfield, CO

Built 2000 Load: 39.3 t ADT: 6,609

123rd Place

Good

Over: Local Drainage

North of Wolff Drive, Broomfield, CO

Built 1996 Load: 40.6 t ADT: 1,232

I 25 ML NBND

Good

Over: NWP

JUST S OF 160TH AVE, Broomfield, CO

Built 2002 Load: 40.6 t ADT: 54,000

SB I-25

Good

Over: NWP/E470

Just South of 160th Ave, Broomfield, CO

Built 2003 Load: 40.6 t ADT: 54,000

Sheridan Pkwy NB

Good

Over: Local Drainage

0.7 Mi W of Lowell, Broomfield, CO

Built 2009 Load: 42.1 t ADT: 5,409

Sheridan Pkwy SB

Good

Over: Local Drainage

0.7 Mi W of Lowell, Broomfield, CO

Built 2009 Load: 42.1 t ADT: 5,192

UPTOWN AVE.

Good

Over: US 36 ML

1.5 MI S of SH128, Broomfield, CO

Built 2014 Load: 44.1 t ADT: 9,653

88TH ST.

Good

Over: US 36 ML

3.5 MI W. OF SH 121, Broomfield, CO

Built 2000 Load: 45.4 t ADT: 8,157

US 36 ML

Good

Over: COAL CREEK

JUST E of SUPERIOR INT., Broomfield, CO

Built 2015 Load: 45.5 t ADT: 66,000

US 36 ML

Good

Over: ROCK CREEK

_, Broomfield, CO

Built 2015 Load: 46.0 t ADT: 68,000

160TH AVE

Good

Over: I-25

Just N of NWPkwy-470, Broomfield, CO

Built 2003 Load: 52.2 t ADT: 10,394

Lowell Street

Good

Over: Local Drainage

.2 Mi N of 136th Avenue, Broomfield, CO

Built 1998 Load: 53.2 t ADT: 12,221

W. Flatiron Circle

Good

Over: Rock Cr and IRR Dtch

200ft N of Flatiron W Ent, Broomfield, CO

Built 2000 Load: 65.7 t ADT: 6,174

Kirk Street

Good

Over: Local Drainage

50 Ft N of E. 1st Street, Broomfield, CO

Built 1999 Load: 68.4 t ADT: 1,384

Read our methodology - how this data is sourced, computed, and verified.

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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.