Total bridges
372
Public highway bridges in Clinton County
County profile · official public datasets
Clinton County, IA
372 public highway bridges tracked in the FHWA National Bridge Inventory: 66.7% rated Good, 30.4% Fair, 3% Poor.
- 372
- Public bridges
- 66.7%
- Good condition
- 3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Clinton County pairs a top-5% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 2%
- lowest Poor share in state
- 3%
- Poor-condition share
- 372
- public highway bridges
- 1986
- 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.
Clinton County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Clinton County ranks #2 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3%). Clinton County, Iowa contains 372 public highway bridges. Roughly 66.7% are rated “Good,” 30.4% “Fair,” and 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.
Good condition
66.7%
248 of 372 rated 7-9
Fair condition
30.4%
113 of 372 rated 5-6
Poor condition
3%
11 of 372 rated 4 or below
In-state Poor-share rank
#2 of 99
Among Iowa counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 372 NBI-tracked bridges by lowest applicable component rating.
Good 66.7% (248)
Fair 30.4% (113)
Poor 3% (11)
Clinton County's Poor-condition bridges carry 4,275 vehicle crossings a day
That is 0.9% of the county's reported daily bridge traffic on 3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 389 crossings a day against 845 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 372 of 372 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
28.8% of Clinton County's bridges have passed the 50-year mark
107 of the 372 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 66.7% 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 33% of the county's Poor-condition bridge traffic
HARTS MILL RD over MILL CREEK, built 1970, carries 1,410 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 11-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,275 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Clinton County's bridges were built
372 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 2
1910–1919
2 bridges
- 1920s 8
1920–1929
8 bridges
- 1930s 3
1930–1939
3 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 25
1950–1959
25 bridges
- 1960s
1960–1969
36 bridges
- 1970s
1970–1979
57 bridges
- 1980s
1980–1989
52 bridges
- 1990s
1990–1999
69 bridges
- 2000s
2000–2009
60 bridges
- 2010s
2010–2019
42 bridges
- 2020s 15
2020–2029
15 bridges
What this shows Construction peaked in the 1990s, when 69 of the county's bridges still in the inventory were built, which is 18.5% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1986, 7 years newer than the Iowa average of 1979.
How Clinton County compares with Iowa's closest counties by inventory size
The 5 Iowa counties nearest Clinton County in number of bridges, with their condition splits. Its 3% Poor share is the 1st-lowest of these 6. Its average build year of 1986 against a peer-group mean of 1981 is 5 years newer.
Showing the 5 closest of 98 Iowa counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Jasper County | 382 | 38.5% | 32.5% | 29.1% | 1977 |
| Benton County | 374 | 34.2% | 42.8% | 23% | 1984 |
| Johnson County | 372 | 39.5% | 50.3% | 10.2% | 1979 |
| Clinton County (this page) | 372 | 66.7% | 30.4% | 3% | 1986 |
| Fayette County | 362 | 35.1% | 40.3% | 24.6% | 1974 |
| Dubuque County | 346 | 50.6% | 40.8% | 8.7% | 1989 |
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 Clinton 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 Clinton County, both outside Iowa so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IA (372 bridges here).
- Harper County, KS · 372 bridges
- Harvey County, KS · 372 bridges
- Wharton County, TX · 372 bridges
- Solano County, CA · 373 bridges
Similar average build year
Nearest mean year-built outside IA (1986 here).
- El Paso County, TX · avg 1986 · 783 bridges
- Caddo County, LA · avg 1986 · 682 bridges
- Weld County, CO · avg 1986 · 614 bridges
- Canadian County, OK · avg 1986 · 493 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (113)
US 30 & 67
FairOver: MILL CREEK
0.2 Mi. E Of W Jct. US 67, Clinton, IA
Built 2000 Load: 31.5 t ADT: 17,300
250TH AVE
FairOver: BLACK CREEK
082E32702, Clinton, IA
Built 1985 Load: 31.7 t ADT: 11
320TH AVE
FairOver: SMALL
083E42604, Clinton, IA
Built 1978 Load: 32.5 t ADT: 350
420TH AVE.
FairOver: CREEK
082E63302, Clinton, IA
Built 1991 Load: 32.6 t ADT: 91
CO RD
FairOver: HARTS MILL CREEK
081050702, Clinton, IA
Built 1983 Load: 32.7 t ADT: 110
S 19TH ST
FairOver: DRAINAGE
081061402, Clinton, IA
Built 1978 Load: 32.7 t ADT: 1,590
230TH ST
FairOver: CREEK
081E51201, Clinton, IA
Built 1952 Load: 32.7 t ADT: 82
160TH ST
FairOver: STREAM
082E40501, Clinton, IA
Built 1962 Load: 32.7 t ADT: 21
400TH AVE.
FairOver: CREEK
083E63002, Clinton, IA
Built 1958 Load: 32.7 t ADT: 40
170TH ST.
FairOver: DRAINAGE
082E10901, Clinton, IA
Built 1987 Load: 32.8 t ADT: 21
120TH AVE.
FairOver: SMALL
082E10504, Clinton, IA
Built 1989 Load: 32.8 t ADT: 21
280TH AVE
FairOver: DEEP CREEK
083E43004, Clinton, IA
Built 1975 Load: 33.1 t ADT: 51
EB US 30
FairOver: S 6TH AVE
1.5 MI. E OF E JCT. US 61, Clinton, IA
Built 1970 Load: 33.1 t ADT: 3,650
EB US 30
FairOver: SILVER CK & UP RR
0.7 MI. E OF W JCT US 61, Clinton, IA
Built 1970 Load: 33.1 t ADT: 8,550
MILL CR. EXPWY.
FairOver: HARTS MILL CREEK
081061505, Clinton, IA
Built 2000 Load: 33.3 t ADT: 8,400
US 67
FairOver: OVER UP RR
0.5 MI. S OF JCT. US 30, Clinton, IA
Built 1978 Load: 33.6 t ADT: 11,000
120TH AVE.
FairOver: CREEK
082E12802, Clinton, IA
Built 1920 Load: 33.7 t ADT: 21
400TH AVE.
FairOver: SOUTH BRANCH ELK RIVER
083E63102, Clinton, IA
Built 1989 Load: 34.4 t ADT: 80
252ND ST
FairOver: SILVER CREEK
081E32305, Clinton, IA
Built 1971 Load: 34.6 t ADT: 760
185TH AVENUE
FairOver: PRAIRIE CREEK
083E20404, Clinton, IA
Built 1973 Load: 34.6 t ADT: 840
110TH ST.
FairOver: PRAIRIE CREEK
083E20901, Clinton, IA
Built 1975 Load: 34.6 t ADT: 90
IA 136
FairOver: DRAINAGE DITCH
8.6 mi. N of jct. US 61, Clinton, IA
Built 1952 Load: 34.8 t ADT: 1,230
IA 136
FairOver: DRAINAGE DITCH
1.4 mi S of Jct. SR Y 32, Clinton, IA
Built 1978 Load: 34.9 t ADT: 1,050
WB US 30
FairOver: AMES CREEK
3.5 MI E OF E JCT US 61, Clinton, IA
Built 1974 Load: 34.9 t ADT: 4,700
160TH ST.
FairOver: DD #12
082E20501, Clinton, IA
Built 1979 Load: 35.3 t ADT: 35
175TH ST
FairOver: DRAINAGE DITCH #12
082E21105, Clinton, IA
Built 1980 Load: 35.3 t ADT: 16
200TH AVE
FairOver: DRAINAGE DITCH #10
082E22302, Clinton, IA
Built 1984 Load: 35.4 t ADT: 60
190TH ST.
FairOver: SMALL STREAM
082E51904, Clinton, IA
Built 1976 Load: 35.5 t ADT: 26
290TH AVE
FairOver: SUGAR CREEK
083E40502, Clinton, IA
Built 1987 Load: 35.6 t ADT: 45
IA 136
FairOver: DEEP CREEK
0.2 mi S. of Jct. SR Z2E, Clinton, IA
Built 1976 Load: 35.8 t ADT: 840
247TH AVE
FairOver: BARBER CREEK
081E33306, Clinton, IA
Built 1985 Load: 35.8 t ADT: 41
110TH ST.
FairOver: CREEK
083E31101, Clinton, IA
Built 1921 Load: 35.8 t ADT: 51
148TH ST.
FairOver: SMALL STREAM
083E32803, Clinton, IA
Built 1968 Load: 35.8 t ADT: 11
WB US 30
FairOver: BROPHYS CREEK
8.5 MI. E OF E JCT. US 61, Clinton, IA
Built 1978 Load: 35.9 t ADT: 5,000
US 30
FairOver: YANKEE RUN CREEK
3.2 mi. W of jct. SR Y4E, Clinton, IA
Built 1954 Load: 36.9 t ADT: 2,540
278TH ST
FairOver: DRAINAGE
080E20205, Clinton, IA
Built 1996 Load: 37.5 t ADT: 170
340TH AVENUE
FairOver: CREEK
082E53102, Clinton, IA
Built 1965 Load: 37.5 t ADT: 35
130TH ST
FairOver: CREEK
083E22301, Clinton, IA
Built 1970 Load: 37.5 t ADT: 16
140TH ST.
FairOver: CREEK
083E32501, Clinton, IA
Built 1967 Load: 37.5 t ADT: 21
US 67
FairOver: WAPSIPINICON OVERFLOW
1.5 mi. S of Sec. Rd. Z36, Clinton, IA
Built 1982 Load: 37.9 t ADT: 4,970
NB US 61
FairOver: SILVER CREEK
0.9 MI. N OF N JCT US 30, Clinton, IA
Built 1974 Load: 37.9 t ADT: 6,350
HART MILL RD
FairOver: HARTS MILL CREEK
081061101, Clinton, IA
Built 1988 Load: 38.3 t ADT: 102
290TH AVE
FairOver: AMES CREEK
081E40502, Clinton, IA
Built 1971 Load: 39.0 t ADT: 1,220
OLD US 61
FairOver: SMALL NATURAL STREAM
083E30606, Clinton, IA
Built 1960 Load: 39.1 t ADT: 1,074
MILL CR. EXPWY.
FairOver: MILL CREEK
081061107, Clinton, IA
Built 2000 Load: 39.2 t ADT: 7,619
CO RD-S 14TH
FairOver: OVER UP RR
081061306, Clinton, IA
Built 1957 Load: 40.3 t ADT: 1,550
US 30
FairOver: DRAINAGE DITCH
1.2 mi. E of Jct. SR Y68, Clinton, IA
Built 1974 Load: 40.3 t ADT: 9,400
260TH AVE
FairOver: CLEAR CREEK
081E31404, Clinton, IA
Built 1995 Load: 40.9 t ADT: 570
IA 136
FairOver: MISSISSIPPI RIVER & RR
IN NORTH CLINTON, Clinton, IA
Built 1974 Load: 42.1 t ADT: 11,000
200TH AVE
FairOver: SMALL
080E20204, Clinton, IA
Built 1979 Load: 42.2 t ADT: 104
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.