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
FairOver: CREEK
089E13006, Dubuque, IA
Built 1975 Load: 24.3 t ADT: 462
FM
FairOver: CREEK
089013607, Dubuque, IA
Built 1973 Load: 25.9 t ADT: 59
US 52
FairOver: DRAINAGE DITCH
7.4 mi S of jct US 61/151, Dubuque, IA
Built 1945 Load: 26.2 t ADT: 3,340
LOCAL
FairOver: SMALL
090E12405, Dubuque, IA
Built 1979 Load: 26.2 t ADT: 60
US 52
FairOver: DRAINAGE DITCH
2.7 MI. N OF JCT. SR C64, Dubuque, IA
Built 1985 Load: 26.6 t ADT: 2,860
FM
FairOver: WHITE WATER CREEK
088013506, Dubuque, IA
Built 1966 Load: 26.6 t ADT: 511
CONRAD LANE
FairOver: WHITEWATER CREEK
088012603, Dubuque, IA
Built 2022 Load: 26.9 t ADT: 11
2ND ST NE
FairOver: N FORK MAQUOKETA RIVER
2ND ST NE - N FORK, Dubuque, IA
Built 1979 Load: 27.2 t ADT: 1,525
US 61
FairOver: BUNCOMBE CREEK
2.0 MI. S OF SR D41, Dubuque, IA
Built 1967 Load: 27.2 t ADT: 8,900
EAST 16TH ST
FairOver: LAKE PEOSTA CHANNEL
000000000, Dubuque, IA
Built 1982 Load: 27.2 t ADT: 9,191
LOCAL
FairOver: CREEK
090E13606, Dubuque, IA
Built 1900 Load: 27.5 t ADT: 5
CALONDER RD
FairOver: MIDDLE MAQUOKETA RIVER
090E13106, Dubuque, IA
Built 1974 Load: 28.6 t ADT: 160
NB US 61
FairOver: 11TH ST
1.0 Mi. N of Jct. US 20, Dubuque, IA
Built 1992 Load: 28.9 t ADT: 11,150
FM
FairOver: KIDDER CREEK
088010204, Dubuque, IA
Built 1985 Load: 29.8 t ADT: 619
FM
FairOver: MAQUOKETA RIVER
089020507, Dubuque, IA
Built 1984 Load: 29.8 t ADT: 412
BELTLINE NW
FairOver: MAQUOKETA RIVER
BELTLINE NW - N FORK, Dubuque, IA
Built 1987 Load: 29.8 t ADT: 1,738
LOCAL
FairOver: MIDDLE FORK MAQUOKETA
089010303, Dubuque, IA
Built 1972 Load: 30.0 t ADT: 290
NB NW ARTERIAL
FairOver: OVER CC RR & CATFISH CK
0.2 MI. N OF JCT. US 20, Dubuque, IA
Built 1982 Load: 30.1 t ADT: 5,295
LOCAL
FairOver: GRANGER CREEK
088E21227, Dubuque, IA
Built 1975 Load: 30.4 t ADT: 480
LOCAL
FairOver: N.FORK MAQUOKETA RIVER
089021901, Dubuque, IA
Built 1967 Load: 30.4 t ADT: 790
3RD ST SW
FairOver: BEAR CREEK
3RD ST SW - BEAR CREEK, Dubuque, IA
Built 1966 Load: 30.5 t ADT: 2,333
SB US 61
FairOver: 11TH ST
1.0 Mi. N. of Jct. US 20., Dubuque, IA
Built 1992 Load: 30.7 t ADT: 11,150
CEDAR CROSS RD
FairOver: MIDDLE FORK CATFISH CRK
S. OF CENTER GROVE DR., Dubuque, IA
Built 1985 Load: 31.4 t ADT: 10,390
LOCAL
FairOver: SMALL STREAM
087023004, Dubuque, IA
Built 1986 Load: 31.5 t ADT: 50
WB US 20
FairOver: N FORK MAQUOKETA RIVER
0.6 MI. W OF JCT. IA 136, Dubuque, IA
Built 1958 Load: 31.8 t ADT: 5,450
ROCKDALE RD
FairOver: OVER CC RR & CATFISH CK
NE OF OLD MILL RD, Dubuque, IA
Built 1986 Load: 32.1 t ADT: 3,302
LOCAL
FairOver: STREAM
090E13505, Dubuque, IA
Built 1981 Load: 32.1 t ADT: 80
LAKE ELEANOR RD
FairOver: SMALL STREAM
00000, Dubuque, IA
Built 1980 Load: 32.1 t ADT: 480
NB US 61/151
FairOver: 4TH 5TH WHITE ST
0.6 mi. N of US 20, Dubuque, IA
Built 1992 Load: 32.3 t ADT: 13,200
CHESTERMAN RD
FairOver: CREEK
088E10203, Dubuque, IA
Built 2014 Load: 32.4 t ADT: 71
FM
FairOver: SMALL STREAM
091E13008, Dubuque, IA
Built 1895 Load: 32.4 t ADT: 45
SYCAMORE ST
FairOver: BEE BRANCH
N OF E 15TH STREET, Dubuque, IA
Built 2011 Load: 32.4 t ADT: 2,147
JACOBY DR W
FairOver: DRAINAGE DITCH
0.2 mi W. of S. Center Av, Dubuque, IA
Built 1960 Load: 32.7 t ADT: 651
IA 3
FairOver: N FORK MAQUOKETA RIVER
1.5 MI. S Jct. IA 136, Dubuque, IA
Built 1968 Load: 32.7 t ADT: 1,720
LOCAL
FairOver: CREEK
087E10303, Dubuque, IA
Built 2002 Load: 32.7 t ADT: 60
FM
FairOver: WHITE WATER CREEK
087011007, Dubuque, IA
Built 1988 Load: 32.7 t ADT: 590
STEGER RD
FairOver: N BR MAQUOKETA RIVER
087021803, Dubuque, IA
Built 2017 Load: 32.7 t ADT: 26
KEMP RD
FairOver: CREEK
088E30706, Dubuque, IA
Built 2000 Load: 32.7 t ADT: 520
LOCAL
FairOver: CREEK
088013304, Dubuque, IA
Built 2001 Load: 32.7 t ADT: 44
FM
FairOver: CREEK
088021505, Dubuque, IA
Built 2001 Load: 32.7 t ADT: 80
SEIPPEL RD
FairOver: MIDDLE FORK CATFISH CRK
N. OF CHAVENELLE RD, Dubuque, IA
Built 1949 Load: 32.7 t ADT: 3,632
LOCAL RD
FairOver: CREEK
089010704, Dubuque, IA
Built 1998 Load: 32.7 t ADT: 11
FM
FairOver: CREEK
090011204, Dubuque, IA
Built 1946 Load: 32.7 t ADT: 160
FM
FairOver: CLOIE CREEK
089E20504, Dubuque, IA
Built 1992 Load: 32.7 t ADT: 1,159
GRAF RD
FairOver: CREEK
089E13204, Dubuque, IA
Built 1985 Load: 32.7 t ADT: 678
CHAVENELLE RD
FairOver: MID FK CATFISH CREEK
W. OF SYNERGY COURT, Dubuque, IA
Built 1998 Load: 32.7 t ADT: 3,011
KEY WAY
FairOver: NORTH FORK CATFISH CREEK
0.04 MI N OF KEYSTONE DR, Dubuque, IA
Built 2010 Load: 32.7 t ADT: 1,932
US 61
FairOver: OTTER CREEK
0.3 MI. N of Jct. SR D55, Dubuque, IA
Built 1967 Load: 32.7 t ADT: 9,000
FM
FairOver: SMALL
087E13006, Dubuque, IA
Built 1978 Load: 33.0 t ADT: 720
FM
FairOver: JOHNS CREEK
088023604, Dubuque, IA
Built 1972 Load: 33.0 t ADT: 680
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.