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.
All bridges (372)
OLD US 61
FairOver: SILVER CREEK
082E31004, Clinton, IA
Built 1926 Load: 0.0 t ADT: 200
SECOND AVE RD
FairOver: SMALL STREAM
081051201, Clinton, IA
Built 1925 Load: 17.0 t ADT: 450
NB US 61
FairOver: WAPSIPINICON OVERFLOW
2.8 miles S of U.S. 30, Clinton, IA
Built 1981 Load: 19.2 t ADT: 8,800
SB US 61
FairOver: WAPSIPINICON OVERFLOW
2.8 miles S of U.S.30, Clinton, IA
Built 1981 Load: 19.2 t ADT: 8,800
US 30
FairOver: OVER UP RR
0.6 mi. E of jct. SR Y4E, Clinton, IA
Built 1955 Load: 21.0 t ADT: 2,550
CO RD Y 62
FairOver: US 30
0.3 mi. W of E Jct. US 61, Clinton, IA
Built 1975 Load: 21.4 t ADT: 760
IA 136
FairOver: E TRIB TO ELWOOD CREEK
1.2 MI. N OF JCT. U.S. 61, Clinton, IA
Built 1929 Load: 21.5 t ADT: 1,000
WB US 30
FairOver: SILVER CK & UP RR
0.7 MI. E OF W JCT. US 61, Clinton, IA
Built 1970 Load: 21.8 t ADT: 8,550
215TH ST
FairOver: DRAINAGE DITCH 11
082E13601, Clinton, IA
Built 1988 Load: 22.7 t ADT: 26
PERSHING BLVD
FairOver: STREAM
082073005, Clinton, IA
Built 1975 Load: 22.7 t ADT: 754
N. 2ND ST.
FairOver: STREAM
082072902, Clinton, IA
Built 1975 Load: 22.7 t ADT: 1,223
N.EAST ST.
FairOver: CREEK
081030802, Clinton, IA
Built 1960 Load: 24.5 t ADT: 360
IA 136
FairOver: ELWOOD CREEK
4.0 MI. N OF JCT. US 61, Clinton, IA
Built 1952 Load: 25.1 t ADT: 1,230
135TH ST.
FairOver: DEEP CR
083E51903, Clinton, IA
Built 1974 Load: 26.3 t ADT: 21
362ND AVENUE
FairOver: SIMMONS CREEK
083E51602, Clinton, IA
Built 1964 Load: 26.6 t ADT: 1,610
105TH ST.
FairOver: RAT RUN CREEK
083E10403, Clinton, IA
Built 1986 Load: 26.8 t ADT: 11
US 30
FairOver: MISSISSIPPI RVR RR S 2ND
IN CLINTON, Clinton, IA
Built 1956 Load: 27.2 t ADT: 11,100
IA 136
FairOver: W TRIB TO ELWOOD CREEK
1.9 MI. N OF JCT. US 61, Clinton, IA
Built 1952 Load: 27.2 t ADT: 1,000
463RD AVENUE
FairOver: CREEK
082E71804, Clinton, IA
Built 1923 Load: 27.2 t ADT: 11
LOCAL CO.LINE
FairOver: SMALL STREAM
083E60103, Clinton, IA
Built 1993 Load: 27.2 t ADT: 78
US 30
FairOver: CALAMUS DRAINAGE DITCH
1.5 MI. W OF SR Y44, Clinton, IA
Built 1955 Load: 27.5 t ADT: 3,430
US 30
FairOver: US 30 & US 61
At E jct. of US 61, Clinton, IA
Built 1975 Load: 27.6 t ADT: 3,200
IA 136
FairOver: ELWOOD CREEK
3.1 MI. N OF JCT. US 61, Clinton, IA
Built 1952 Load: 27.8 t ADT: 1,000
135TH ST.
FairOver: ELK RIVER
083E72003, Clinton, IA
Built 1986 Load: 27.8 t ADT: 41
WB US 30
FairOver: S 6TH AVE
1.5 MI. E OF E JCT. US 61, Clinton, IA
Built 1970 Load: 27.8 t ADT: 3,650
100TH ST.
FairOver: CREEK
083E30607, Clinton, IA
Built 1959 Load: 27.9 t ADT: 29
US 30
FairOver: WAPSIPINICON RIVER
1.0 MI. E OF SR Y4E, Clinton, IA
Built 1955 Load: 28.1 t ADT: 2,550
425TH AVENUE
FairOver: ELK RIVER
083E62104, Clinton, IA
Built 1991 Load: 28.1 t ADT: 26
100TH ST
FairOver: ELK RIVER
083E60501, Clinton, IA
Built 1950 Load: 28.2 t ADT: 78
US 30
FairOver: WAPSIPINICON RIVER
1.5 mi E of Jct SR Y4E, Clinton, IA
Built 1955 Load: 28.9 t ADT: 3,430
US 30 EB
FairOver: UP RR
5.8 MI. E OF S JCT. US 61, Clinton, IA
Built 1974 Load: 28.9 t ADT: 4,700
US 30
FairOver: E CHAN WAPSIPINICON RVR
2.3 mi. E of Jct SR Y4E, Clinton, IA
Built 1955 Load: 29.0 t ADT: 3,430
118TH AVENUE
FairOver: WAPSIPINICON RIVER
082E11704, Clinton, IA
Built 1963 Load: 29.0 t ADT: 350
EB US 30
FairOver: BROPHYS CREEK
8.5 MI. E OF E JCT. US 61, Clinton, IA
Built 1969 Load: 29.4 t ADT: 5,000
US 67
FairOver: WAPSIPINICON OVERFLOW
0.7 MI. S OF FOLLETTS, Clinton, IA
Built 1983 Load: 29.4 t ADT: 4,970
225TH ST.
FairOver: SMALL STREAM
081E10303, Clinton, IA
Built 1994 Load: 29.4 t ADT: 26
135TH STREET
FairOver: SMALL STREAM
083E52003, Clinton, IA
Built 1984 Load: 29.4 t ADT: 35
197TH ST
FairOver: CHERRY CREEK
082E42405, Clinton, IA
Built 1980 Load: 29.8 t ADT: 73
SO 30TH ST
FairOver: HARTS MILL CREEK
081061502, Clinton, IA
Built 1978 Load: 30.0 t ADT: 180
410TH AVE.
FairOver: SOUTH BRANCH ELK RIVER
083E62902, Clinton, IA
Built 1989 Load: 30.0 t ADT: 62
210TH AVENUE
FairOver: DRAINAGE DITCH 5
080E20104, Clinton, IA
Built 1965 Load: 30.3 t ADT: 750
220TH STREET
FairOver: BROPHY CREEK
081E50403, Clinton, IA
Built 1964 Load: 30.3 t ADT: 1,010
350TH AVE
FairOver: BROPHY CREEK
081E52002, Clinton, IA
Built 1964 Load: 30.3 t ADT: 460
190TH STREET
FairOver: DRAINAGE DITCH 12
082E21901, Clinton, IA
Built 1967 Load: 30.3 t ADT: 320
190TH STREET
FairOver: SILVER CREEK WEST
082E32201, Clinton, IA
Built 1968 Load: 30.3 t ADT: 800
140TH STREET
FairOver: SPRING CREEK
083E62801, Clinton, IA
Built 1963 Load: 30.3 t ADT: 860
130TH AVENUE
FairOver: YANKEE RUN CREEK
081E11504, Clinton, IA
Built 1968 Load: 30.4 t ADT: 10
250TH AVENUE
FairOver: DEEP CREEK
083E32704, Clinton, IA
Built 1968 Load: 30.4 t ADT: 950
US 30 WB
FairOver: UP RR
5.8 MI. E OF S JCT. US 61, Clinton, IA
Built 1974 Load: 30.5 t ADT: 4,500
EB US 30
FairOver: AMES CREEK
3.5 MI E OF E JCT US 61, Clinton, IA
Built 1974 Load: 31.1 t ADT: 4,700
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.