Total bridges
464
Public highway bridges in Jefferson County
County profile · official public datasets
464 public highway bridges tracked in the FHWA National Bridge Inventory: 33.8% rated Good, 59.9% Fair, 6.3% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Jefferson County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
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.
According to the Federal Highway Administration's 2024 National Bridge Inventory, Jefferson County ranks #40 of 64 Colorado counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.3%). Jefferson County, Colorado contains 464 public highway bridges. Roughly 33.8% are rated “Good,” 59.9% “Fair,” and 6.3% “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
464
Public highway bridges in Jefferson County
Good condition
33.8%
157 of 464 rated 7-9
Fair condition
59.9%
278 of 464 rated 5-6
Poor condition
6.3%
29 of 464 rated 4 or below
In-state Poor-share rank
#40 of 64
Among Colorado counties with 5+ bridges, lower share ranks better
Share of 464 NBI-tracked bridges by lowest applicable component rating.
That is 10.1% of the county's reported daily bridge traffic on 6.3% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 29,429 crossings a day against 16,847 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 464 of 464 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
154 of the 464 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 33.8% 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.
US 6 ML over SH 121 ML, built 1972, carries 101,000 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 29-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 853,450 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
464 bridges with a recorded construction year, grouped by decade
1920–1929
1 bridges
1930–1939
11 bridges
1940–1949
12 bridges
1950–1959
26 bridges
1960–1969
59 bridges
1970–1979
80 bridges
1980–1989
93 bridges
1990–1999
78 bridges
2000–2009
56 bridges
2010–2019
37 bridges
2020–2029
11 bridges
What this shows Construction peaked in the 1980s, when 93 of the county's bridges still in the inventory were built, which is 20% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1984) matches the Colorado average (1982).
The 5 Colorado counties nearest Jefferson County in number of bridges, with their condition splits. Its 6.3% Poor share is the 4th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1987 is in line with the group.
Showing the 5 closest of 63 Colorado counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Larimer County | 559 | 49% | 49% | 2% | 1987 |
| Adams County | 535 | 43.9% | 49.2% | 6.9% | 1990 |
| Jefferson County (this page) | 464 | 33.8% | 59.9% | 6.3% | 1984 |
| Denver County | 458 | 41.9% | 56.3% | 1.7% | 1991 |
| Arapahoe County | 391 | 26.1% | 66.8% | 7.2% | 1984 |
| Mesa County | 319 | 35.1% | 63.3% | 1.6% | 1981 |
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 Jefferson County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Jefferson County, both outside Colorado so the neighborhoods are not the same-state size table above.
Nearest county inventories outside CO (464 bridges here).
Nearest mean year-built outside CO (1984 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: BEAR CREEK
AT INTER. WITH SH 8, Jefferson, CO
Over: US 36 ML
JUST W OF SHERIDAN BLVD, Jefferson, CO
Over: RALSTON CREEK
0.06 MI NORTH OF 68TH AVE, Jefferson, CO
Over: I 70 ML SH 121 R
IN ARVADA, Jefferson, CO
Over: BUFFALO CREEK
4.4 MI FROM CR 126, Jefferson, CO
Over: VAN BIBBER CREEK
JUST NORTH OF 60TH PLACE, Jefferson, CO
Over: I 70 ML
JCT. I70 & 470, Jefferson, CO
Over: FARMERS HIGHLINE CANAL
INDIANA ST ABOUT 7800 N, Jefferson, CO
Over: CLEAR CREEK
S. edge 70 76 ramp 121, Jefferson, CO
Over: BEAR CREEK
AT INTER WITH SH 8, Jefferson, CO
Over: I 70 ML
1.8 MI E OF JCT SH 74, Jefferson, CO
Over: RALSTON CREEK
0.06 MI N OF 58TH AVENUE, Jefferson, CO
Over: MASSEY DRAW AR
.1 MI N.OF JCT470&KIPLING, Jefferson, CO
Over: CROKE CANAL
.1 MI W OF CARR STREET, Jefferson, CO
Over: DRAINAGE
W. OF KIPLING STREET, Jefferson, CO
Over: RALSTON CREEK
JUST SOUTH OF BROOKS DR, Jefferson, CO
Over: STRAINS GULCH
0.75 MI S OF MORRISON, Jefferson, CO
Over: VAN BIBBER CREEK
JUST SOUTH OF 58TH AVENUE, Jefferson, CO
Over: COUNTY RD. 93
MORRISON INTCHNG, Jefferson, CO
Over: WEIR GULCH
AT KENTUCKY AVENUE, Jefferson, CO
Over: FARMERS HIGHLINE CANAL
0.1 MI NORTH OF 80TH AVE, Jefferson, CO
Over: CROKE CANAL
0.15 MI NORTH OF 80TH AVE, Jefferson, CO
Over: VAN BIBBER CREEK
WARD RD ARVADA, Jefferson, CO
Over: KERR GULCH
0.8 MI E OF KITTREDGE, Jefferson, CO
Over: SOUTH TURKEY CREEK
3 MI S OF TINYTOWN, Jefferson, CO
Over: CLEAR CREEK
.71 MI EAST OF KIPLING, Jefferson, CO
Over: TURKEY CREEK
JUST SOUTH OF US285, Jefferson, CO
Over: ELK CREEK
4.3 MI E OF JCT SH 119, Jefferson, CO
Over: SOUTH PLATTE RIVER
.1 MI N OF DECKERS, Jefferson, CO
Over: CROKE CANAL
.28 MI E OF KIPLING ST, Jefferson, CO
Over: COUNTY RD 93
Morrison-Red Rocks Int., Jefferson, CO
Over: LENA GULCH
0.7 MI E OF W COLFAX, Jefferson, CO
Over: MASSEY DRAW
.1 MI E OF GARRISON, Jefferson, CO
Over: FARMERS HIGHLINE CANAL
.15 MI E OF KIPLING ST, Jefferson, CO
Over: CLEAR CREEK
5.1 MI E OF JCT SH 119, Jefferson, CO
Over: SOUTH TURKEY CREEK
3.9 MI S OF TINYTOWN, Jefferson, CO
Over: I 70 ML
AT JCT I 70 EL RANCHO, Jefferson, CO
Over: UPPER BEAR CREEK
3 MI W JCT EVERGN LAKE, Jefferson, CO
Over: COON CREEK
0.5 MI S OF BELLEVIEW AVE, Jefferson, CO
Over: BEAR CREEK
CORWINA PARK, Jefferson, CO
Over: MCINTYRE GULCH
IN LAKEWOOD, Jefferson, CO
Over: CLEAR CREEK R
IN WHEATRIDGE, Jefferson, CO
Over: SOUTH PLATTE RIVER
INT OF CO RDS 67 & 97, Jefferson, CO
Over: CLEAR CREEK
WHEATRIDGE, Jefferson, CO
Over: UPPER BEAR CREEK
2.6 MI W JCT EVERGRN LAKE, Jefferson, CO
Over: LAKEWOOD GULCH
JUST NORTH OF 9TH AVENUE, Jefferson, CO
Over: CROKE CANAL
WEST OF INDIANA STREET, Jefferson, CO
Over: ARVADA CHANNEL
0.1 MI. N. OF I 76, Jefferson, CO
Over: US 285 ML
2 MI S OF MORRISON, Jefferson, CO
Over: COAL CREEK
0.25 MI N OF SH 72, Jefferson, CO
Read our methodology - how this data is sourced, computed, and verified.
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.