Boulder County, CO

311 public highway bridges

Boulder County Bridge Snapshot

Boulder County, Colorado contains 311 public highway bridges in the FHWA National Bridge Inventory. Roughly 33.4% are rated “Good,” 60.5% “Fair,” 2.3% “Poor,” and 2.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in CO are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

311
Total Bridges
33.4%
Good
2.3%
Poor
2.3%
Structurally Deficient

Condition Distribution

Good
33.4% (104)
Fair
60.5% (188)
Poor
2.3% (7)
SD
2.3% (7)

All Bridges (311)

SH 119 ML SBND

Good

Over: LEFT HAND CREEK

3.6 MI N OF JCT SH 52, Boulder, CO

Built 1975 Load: 37.5 t ADT: 14,000

County Road 81

Good

Over: Lefthand Creek

250 ft N of Lee Hill Dr, Boulder, CO

Built 2019 Load: 38.2 t ADT: 735

County Line Road

Good

Over: Spring Gulch #2

0.20 MI N. OF E 9TH AVE, Boulder, CO

Built 2021 Load: 38.6 t ADT: 15,509

96th Street

Good

Over: Coal Creek

0.15 Mi. S. of SH42, Boulder, CO

Built 2006 Load: 38.6 t ADT: 15,821

Flagstaff Rd CR56

Good

Over: HIllside Slide

1.0 Mi W of Baseline Rd, Boulder, CO

Built 2014 Load: 38.9 t ADT: 2,463

SH 119 ML, E.Bnd

Good

Over: LEFT HAND CREEK

3.6 MI NE OF SH 52, Boulder, CO

Built 2003 Load: 38.9 t ADT: 24,000

Anderson Hill St

Good

Over: James Creek

200 Ft S of Main St, Boulder, CO

Built 2016 Load: 38.9 t ADT: 117

Martin Street

Good

Over: Left Hand Creek

0.2 MI S Ken Pratt Blvd, Boulder, CO

Built 2016 Load: 38.9 t ADT: 2,572

N. 95th St (Cr 19)

Good

Over: Liggett Ditch

1.2 Mi S of Co Rd 38, Boulder, CO

Built 1984 Load: 39.6 t ADT: 7,744

US 287 NBND

Good

Over: ROCK CREEK

0.4 MI S of NW PKWY, Boulder, CO

Built 1993 Load: 39.9 t ADT: 16,500

US 287 ML SBND

Good

Over: ROCK CREEK

2.2 MI NO OF JCT SH 121, Boulder, CO

Built 1994 Load: 39.9 t ADT: 16,500

S Pratt Parkway

Good

Over: Left Hand Creek

At Missouri Avenue, Boulder, CO

Built 2012 Load: 40.1 t ADT: 4,798

17th Avenue

Good

Over: Spring Gulch

750 Ft E of Whitehall Dr, Boulder, CO

Built 2000 Load: 40.2 t ADT: 9,396

Valmont Rd

Good

Over: Boulder Creek

200 Ft. E of 55th Street, Boulder, CO

Built 1999 Load: 40.5 t ADT: 14,324

SH 93 ML

Good

Over: Bear Creek Ditch

1/2 MI S OF BOULDER LIMIT, Boulder, CO

Built 1969 Load: 40.8 t ADT: 17,000

95 Street (CR 19)

Good

Over: Boulder Creek

1.7 Mi S of CR28, Boulder, CO

Built 2010 Load: 41.5 t ADT: 7,778

Flagstaff Rd CR56

Good

Over: Hillside Slide

1.0 Mi W of Baseline Rd, Boulder, CO

Built 1996 Load: 41.5 t ADT: 2,463

N 81st St (Cr 31)

Good

Over: Left Hand Creek

0.1 M N of Oxford Rd (26), Boulder, CO

Built 1992 Load: 41.9 t ADT: 182

SH 119 ML, W.Bnd

Good

Over: LEFTHAND CREEK

3.6 MI NE OF SH 52, Boulder, CO

Built 2003 Load: 43.1 t ADT: 24,000

SH 119 ML EBND

Good

Over: ST VRAIN RIVER

NEAR LONGMONT, Boulder, CO

Built 2003 Load: 43.1 t ADT: 12,000

Spring Creek Place

Good

Over: Wonderland Creek

570 ft from 34th St., Boulder, CO

Built 2017 Load: 43.4 t

SH 157 NBND

Good

Over: FOUR MILE CANYON CREEK

TWO MILES N OF BOULDER CI, Boulder, CO

Built 1988 Load: 43.6 t ADT: 20,500

IRIS AVENUE

Good

Over: WONDERLAND CREEK

0.2 MI East of 30th St, Boulder, CO

Built 2020 Load: 43.7 t ADT: 1,988

Arapahoe Avenue

Good

Over: Boulder Creek

0.08 Mi E of S. Broadway, Boulder, CO

Built 1988 Load: 45.3 t ADT: 10,452

US 36 ML

Good

Over: SOUTH BOULDER CREEK

2.4 MI E OF JCT SH 93, Boulder, CO

Built 1951 Load: 45.4 t ADT: 77,000

Wagonwheel Gap Rd

Good

Over: Fourmile Creek

200 ft W of Lee Hill Dr, Boulder, CO

Built 2019 Load: 45.7 t ADT: 630

SH 157 SBND

Good

Over: FOUR MILE CANYON CREEK

.25 MI S OF SH119 INTSN, Boulder, CO

Built 1988 Load: 46.4 t ADT: 20,500

County Road 26

Good

Over: Left Hand Creek

0.6 Mi W of Co Rd 33, Boulder, CO

Built 1991 Load: 46.8 t ADT: 121

Logan Mill Road

Good

Over: Four Mile Creek

20 ft W of Four Mi Cny Dr, Boulder, CO

Built 2019 Load: 47.6 t ADT: 238

Dillon Road

Good

Over: Rock Creek

0.3 Mi W of Hwy 287, Boulder, CO

Built 2019 Load: 47.6 t ADT: 451

N. 63rd St (CR39)

Good

Over: Leggett Ditch

0.4 MI N of SH7, Boulder, CO

Built 2015 Load: 48.0 t ADT: 3,275

Pace Street

Good

Over: Spring Gulch

.15 Mi. N of Wyndemere, Boulder, CO

Built 2000 Load: 49.7 t ADT: 7,639

Hygiene Rd (Cr 10)

Good

Over: Boulder Feeder Ditch

0.7 Mi E of US Hwy 36, Boulder, CO

Built 1987 Load: 50.3 t ADT: 692

N. 119th St (Cr 3)

Good

Over: St. Vrain Creek

0.5 Mi N of Co Rd 20, Boulder, CO

Built 1988 Load: 52.1 t ADT: 3,288

FDR 114

Good

Over: MIDDLE ST. VRAIN CREEK

.2 MI W OF CO HWY 72, Boulder, CO

Built 1952 Load: 52.8 t ADT: 198

US 36 ML

Good

Over: ST VRAIN CREEK

IN LYONS, Boulder, CO

Built 2000 Load: 54.0 t ADT: 8,200

South Sunset St.

Good

Over: Left Hand Creek

200 ft N of Creekside Dr, Boulder, CO

Built 2000 Load: 55.1 t ADT: 1,274

FDR 114

Good

Over: MIDDLE ST. VRAIN CREEK

0.94 MI WEST OF CO HWY 72, Boulder, CO

Built 1952 Load: 56.1 t ADT: 90

Bow Mountain Rd.

Good

Over: Fourmile Creek

20 ft S of Wagonwheel Rd, Boulder, CO

Built 2019 Load: 56.1 t ADT: 124

SH 119 NBND

Good

Over: DRY CREEK

4.5 MI NE OF JCT US 36, Boulder, CO

Built 1959 Load: 60.2 t ADT: 18,500

Olympia Avenue

Good

Over: Spring Gulch

200 feet E of Boise Court, Boulder, CO

Built 2000 Load: 61.0 t ADT: 1,207

Main Street

Good

Over: James Creek

Inter of Main and Mill, Boulder, CO

Built 2018 Load: 64.8 t ADT: 180

County Road 81

Good

Over: James Creek

25 ft S of Lefthand Cyn, Boulder, CO

Built 2019 Load: 65.8 t ADT: 777

CoRd94(LH Cnyn RD)

Good

Over: LEFTHAND CREEK

0.6 Mi W of Oldstage Rd, Boulder, CO

Built 2016 Load: 68.0 t ADT: 1,681

US 287

Good

Over: DRAW

JUST N OF NW PKWY, Boulder, CO

Built 1993 Load: 68.3 t ADT: 39,000

N 115th St

Good

Over: Highland Ditch

0.95 Mi N of Vermillion R, Boulder, CO

Built 2012 Load: 69.3 t ADT: 435

Wagonwheel Gap Rd

Good

Over: Four Mile Creek

0.6 Mi W of Lee Hill Rd, Boulder, CO

Built 2019 Load: 69.7 t ADT: 587

27th Way

Good

Over: Skunk Creek

0.2 Mi No of St Hwy 93, Boulder, CO

Built 2008 Load: 74.8 t ADT: 10,468

SH 52 ML

Good

Over: BOULDER CREEK

2.4 MI E OF JCT US 287, Boulder, CO

Built 2011 Load: 75.8 t ADT: 14,000

Iris Ave

Good

Over: Elmers Two Mile Ditch

0.15 Mi W of US36/28th St, Boulder, CO

Built 2005 Load: 81.6 t ADT: 21,112

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

Related

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial