Total bridges
346
Public highway bridges in Dubuque County
County profile · official public datasets
Dubuque County, IA
346 public highway bridges tracked in the FHWA National Bridge Inventory: 50.6% rated Good, 40.8% Fair, 8.7% Poor.
- 346
- Public bridges
- 50.6%
- Good condition
- 8.7%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Dubuque 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 13%
- lowest Poor share in state
- 8.7%
- Poor-condition share
- 346
- public highway bridges
- 1989
- 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.
Dubuque County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Dubuque County ranks #13 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.7%). Dubuque County, Iowa contains 346 public highway bridges. Roughly 50.6% are rated “Good,” 40.8% “Fair,” and 8.7% “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.
Good condition
50.6%
175 of 346 rated 7-9
Fair condition
40.8%
141 of 346 rated 5-6
Poor condition
8.7%
30 of 346 rated 4 or below
In-state Poor-share rank
#13 of 99
Among Iowa counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 346 NBI-tracked bridges by lowest applicable component rating.
Good 50.6% (175)
Fair 40.8% (141)
Poor 8.7% (30)
Dubuque County's Poor-condition bridges carry 9,093 vehicle crossings a day
That is 1.2% of the county's reported daily bridge traffic on 8.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 303 crossings a day against 2,143 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 345 of 346 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
23.1% of Dubuque County's bridges have passed the 50-year mark
80 of the 346 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 50.6% 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 20.6% of the county's Poor-condition bridge traffic
OLD IA 966 over OVER CC RR, built 1936, carries 1,876 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 30-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 9,093 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Dubuque County's bridges were built
346 bridges with a recorded construction year, grouped by decade
- pre-1900 1
Built before 1900
1 bridges
- 1900s 5
1900–1909
5 bridges
- 1910s 2
1910–1919
2 bridges
- 1920s 8
1920–1929
8 bridges
- 1930s 10
1930–1939
10 bridges
- 1940s 12
1940–1949
12 bridges
- 1950s 11
1950–1959
11 bridges
- 1960s 16
1960–1969
16 bridges
- 1970s 30
1970–1979
30 bridges
- 1980s
1980–1989
50 bridges
- 1990s
1990–1999
49 bridges
- 2000s
2000–2009
50 bridges
- 2010s
2010–2019
84 bridges
- 2020s 18
2020–2029
18 bridges
What this shows Construction peaked in the 2010s, when 84 of the county's bridges still in the inventory were built, which is 24.3% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year is 1989, 10 years newer than the Iowa average of 1979.
How Dubuque County compares with Iowa's closest counties by inventory size
The 5 Iowa counties nearest Dubuque County in number of bridges, with their condition splits. Its 8.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1989 against a peer-group mean of 1976 is 13 years newer.
Showing the 5 closest of 98 Iowa counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Clinton County | 372 | 66.7% | 30.4% | 3% | 1986 |
| Johnson County | 372 | 39.5% | 50.3% | 10.2% | 1979 |
| Fayette County | 362 | 35.1% | 40.3% | 24.6% | 1974 |
| Dubuque County (this page) | 346 | 50.6% | 40.8% | 8.7% | 1989 |
| Winneshiek County | 342 | 37.1% | 45.3% | 17.5% | 1967 |
| Tama County | 337 | 34.4% | 31.2% | 34.4% | 1976 |
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 Dubuque 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 Dubuque County, both outside Iowa so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IA (346 bridges here).
- Macon County, IL · 346 bridges
- Whitman County, WA · 347 bridges
- Navarro County, TX · 345 bridges
- Fillmore County, MN · 348 bridges
Similar average build year
Nearest mean year-built outside IA (1989 here).
- Harris County, TX · avg 1989 · 4,029 bridges
- Mecklenburg County, NC · avg 1989 · 746 bridges
- Buffalo County, NE · avg 1989 · 459 bridges
- Brazos County, TX · avg 1989 · 370 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (346)
FM
GoodOver: LYTLE CREEK
087E20403, Dubuque, IA
Built 1982 Load: 22.7 t ADT: 1,270
FM
GoodOver: CREEK
087013104, Dubuque, IA
Built 1977 Load: 22.7 t ADT: 510
FARLEY RD
GoodOver: STREAM
000000000, Dubuque, IA
Built 2009 Load: 22.7 t ADT: 680
FM
GoodOver: CREEK
000000000, Dubuque, IA
Built 2009 Load: 22.7 t ADT: 680
LOCAL
GoodOver: CREEK
089E10204, Dubuque, IA
Built 1973 Load: 22.7 t ADT: 25
LOCAL
GoodOver: CREEK
089E12905, Dubuque, IA
Built 1972 Load: 22.7 t ADT: 59
US 52
GoodOver: LUX CREEK
6.9 MI. S Jct US 61 & 151, Dubuque, IA
Built 1986 Load: 24.3 t ADT: 3,340
MASSEY MARINA LANE
GoodOver: SMALL CREEK
088E31404, Dubuque, IA
Built 2018 Load: 24.3 t ADT: 320
US 20 & 52
GoodOver: DRAINAGE DITCH
0.2 MI. E OF JCT. IA 136, Dubuque, IA
Built 1988 Load: 25.3 t ADT: 7,200
US 20 WB US 52 NB
GoodOver: Y 17 (EPWORTH)
AT JCT. of SR Y17, Dubuque, IA
Built 1988 Load: 26.0 t ADT: 6,800
FM
GoodOver: CREEK
000000000, Dubuque, IA
Built 2009 Load: 27.2 t ADT: 668
LOVERS LANE
GoodOver: CREEK
090E20905, Dubuque, IA
Built 2019 Load: 28.2 t ADT: 45
US 151 NB
GoodOver: BRANCH PRAIRIE CREEK
1.9 MI. N of Jct. SR Y21, Dubuque, IA
Built 1970 Load: 28.3 t ADT: 5,500
CENTRAL AVE
GoodOver: UNION HOLLOW
At Jct. Iowa #32, Dubuque, IA
Built 1967 Load: 28.8 t ADT: 9,690
SB US 61/151
GoodOver: 7TH ST
0.3 M. S OF JCT. IA. 3, Dubuque, IA
Built 1992 Load: 28.8 t ADT: 11,150
NB US 61/151
GoodOver: 7TH ST
0.3 M. S OF JCT. IA. 3, Dubuque, IA
Built 1992 Load: 30.8 t ADT: 11,150
WB US 20
GoodOver: US 52 SB
AT JCT. IA 136, Dubuque, IA
Built 1987 Load: 31.3 t ADT: 3,600
LOCAL
GoodOver: HICKORY CREEK
089021503, Dubuque, IA
Built 1984 Load: 31.8 t ADT: 59
Y21 SUNDOWN RD
GoodOver: US 20 US 52
AT JCT SR- Y21, Dubuque, IA
Built 1987 Load: 31.9 t ADT: 6,285
SB US 61/151
GoodOver: EAST 9TH ST & CN RR
Over E 9th street, Dubuque, IA
Built 1992 Load: 32.0 t ADT: 11,150
HIDDEN VALLEY LANE
GoodOver: STREAM
08802E2506, Dubuque, IA
Built 2021 Load: 32.1 t ADT: 128
US 20 EB
GoodOver: S FORK CATFISH CREEK
US 20 & IA 52 INTERCHANGE, Dubuque, IA
Built 2017 Load: 32.4 t ADT: 8,700
US 20 WB
GoodOver: S FORK CATFISH CREEK
US 20 & IA 52 INTERCHANGE, Dubuque, IA
Built 2018 Load: 32.4 t ADT: 8,700
IA 136
GoodOver: N FORK MAQUOKETA RIVER
2.0 MI. N. OF US 151, Dubuque, IA
Built 2017 Load: 32.4 t ADT: 2,140
FM
GoodOver: CATFISH CREEK
088E22005, Dubuque, IA
Built 2017 Load: 32.4 t ADT: 737
DERBY GRANGE RD
GoodOver: CLOIE BRANCH
089E20805, Dubuque, IA
Built 2011 Load: 32.4 t ADT: 638
N CASCADE RD
GoodOver: SOUTH FORK CATFISH CREEK
88N02ES33NW, Dubuque, IA
Built 2012 Load: 32.4 t ADT: 2,259
SOUTH MOUND RD
GoodOver: NO FORK MAQUOKETA RIVER
9001 28 2010, Dubuque, IA
Built 2016 Load: 32.4 t ADT: 250
N CASCADE RD
GoodOver: US 52
2.7 mi. W of jct. US 20, Dubuque, IA
Built 2011 Load: 32.4 t ADT: 2,259
BRUNSKILL RD
GoodOver: NORTH CATFISH CREEK
W. OF SOUTH GATE DR., Dubuque, IA
Built 2013 Load: 32.4 t ADT: 865
E 16TH ST
GoodOver: BEE BRANCH
W OF SYCAMORE ST, Dubuque, IA
Built 2011 Load: 32.4 t ADT: 4,265
US 61 & 151 SB
GoodOver: CATFISH CR RR & RD
0.7 MI S of Grandview Av, Dubuque, IA
Built 2014 Load: 32.4 t ADT: 9,600
US 61 & 151 NB
GoodOver: CATFISH CR RR & RD
0.7 MI S of Grandview Av, Dubuque, IA
Built 2014 Load: 32.4 t ADT: 9,550
SWISS VALLEY ROAD
GoodOver: US 20
2.8 Mi S of Jct. US 52, Dubuque, IA
Built 2021 Load: 32.4 t ADT: 196
ENGLISH MILL RD
GoodOver: US 52
0.7 MI. E. OF US 20, Dubuque, IA
Built 2017 Load: 32.4 t ADT: 628
MILITARY RD
GoodOver: US 52
MILITARY RD INTERSECTION, Dubuque, IA
Built 2017 Load: 32.4 t ADT: 1,817
US 52
GoodOver: US 20
IA 32 OVER US20 IN DUBUQU, Dubuque, IA
Built 2019 Load: 32.4 t ADT: 6,000
US 20 EB ON RAMP
GoodOver: S FORK CATFISH CREEK
US 20 & IA 52 SW ARTERIAL, Dubuque, IA
Built 2019 Load: 32.4 t ADT: 2,420
US 20 ON RAMP
GoodOver: S FORK CATFISH CREEK
US 20 & IA 52 SW ARTERIAL, Dubuque, IA
Built 2018 Load: 32.4 t ADT: 1,570
US 52 NB
GoodOver: CATFISH CREEK
US 52 NB OVER CATFISH CRK, Dubuque, IA
Built 2019 Load: 32.4 t ADT: 3,150
US 52
GoodOver: US 61/151 GRANGER CREEK
US 61/151 & IA 32 INTRCHG, Dubuque, IA
Built 2019 Load: 32.4 t ADT: 1,770
AIRBORNE ROAD
GoodOver: S FORK CATFISH CREEK
0.2 MI. S. OF SEIPPEL RD., Dubuque, IA
Built 2019 Load: 32.4 t ADT: 110
N CASCADE CONNECTR
GoodOver: US 52
N CASCADE CONNECTR, Dubuque, IA
Built 2018 Load: 32.4 t ADT: 432
US 52 SB
GoodOver: CATFISH CREEK
US 52 SB OVER CATFISH CRK, Dubuque, IA
Built 2019 Load: 32.4 t ADT: 3,150
E 32ND ST-PERU
GoodOver: BORDEAUX RUN
N OF LIBERTY ST, Dubuque, IA
Built 1993 Load: 32.7 t ADT: 5,395
LOCAL
GoodOver: WHITE WATER CREEK
087E10603, Dubuque, IA
Built 2006 Load: 32.7 t ADT: 71
FM
GoodOver: LYTLE CREEK
087E13608, Dubuque, IA
Built 1994 Load: 32.7 t ADT: 370
TARA LANE
GoodOver: STREAM
087011005, Dubuque, IA
Built 2021 Load: 32.7 t ADT: 20
TYLER ST NE
GoodOver: CREEK
000000000, Dubuque, IA
Built 2005 Load: 32.7 t ADT: 509
LOCAL
GoodOver: WHITE WATER CREEK
087013604, Dubuque, IA
Built 1999 Load: 32.7 t ADT: 71
Read our methodology - how this data is sourced, computed, and verified.
Related
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.