Total bridges
179
Public highway bridges in Carroll County
County profile · official public datasets
Carroll County, IL
179 public highway bridges tracked in the FHWA National Bridge Inventory: 37.4% rated Good, 52% Fair, 10.6% Poor.
- 179
- Public bridges
- 37.4%
- Good condition
- 10.6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Carroll County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 78th
- of 102 on Poor share
- 10.6%
- Poor-condition share
- 179
- public highway bridges
- 1979
- 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.
Carroll County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Carroll County ranks #78 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.6%). Carroll County, Illinois contains 179 public highway bridges. Roughly 37.4% are rated “Good,” 52% “Fair,” and 10.6% “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
37.4%
67 of 179 rated 7-9
Fair condition
52%
93 of 179 rated 5-6
Poor condition
10.6%
19 of 179 rated 4 or below
In-state Poor-share rank
#78 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 179 NBI-tracked bridges by lowest applicable component rating.
Good 37.4% (67)
Fair 52% (93)
Poor 10.6% (19)
Carroll County's Poor-condition bridges carry 4,750 vehicle crossings a day
That is 4% of the county's reported daily bridge traffic on 10.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 250 crossings a day against 573 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 179 of 179 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
31.3% of Carroll County's bridges have passed the 50-year mark
56 of the 179 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 37.4% 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 49.5% of the county's Poor-condition bridge traffic
ARGO FAY ROAD over STREAM, built 1937, carries 2,350 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 19-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,750 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Carroll County's bridges were built
179 bridges with a recorded construction year, grouped by decade
- pre-1900 2
Built before 1900
2 bridges
- 1910s 1
1910–1919
1 bridges
- 1920s 9
1920–1929
9 bridges
- 1930s 6
1930–1939
6 bridges
- 1940s 4
1940–1949
4 bridges
- 1950s 14
1950–1959
14 bridges
- 1960s 13
1960–1969
13 bridges
- 1970s
1970–1979
22 bridges
- 1980s
1980–1989
47 bridges
- 1990s
1990–1999
31 bridges
- 2000s 16
2000–2009
16 bridges
- 2010s 11
2010–2019
11 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1980s, when 47 of the county's bridges still in the inventory were built, which is 26.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1979) matches the Illinois average (1979).
How Carroll County compares with Illinois's closest counties by inventory size
The 5 Illinois counties nearest Carroll County in number of bridges, with their condition splits. Its 10.6% Poor share is the 5th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1981 is in line with the group.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Lawrence County | 185 | 36.2% | 41.1% | 22.7% | 1975 |
| Saline County | 185 | 71.4% | 23.8% | 4.9% | 1985 |
| Jasper County | 181 | 70.7% | 24.3% | 5% | 1982 |
| Carroll County (this page) | 179 | 37.4% | 52% | 10.6% | 1979 |
| Moultrie County | 172 | 39% | 51.2% | 9.9% | 1984 |
| Cumberland County | 169 | 54.4% | 39.1% | 6.5% | 1979 |
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 Carroll 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 Carroll County, both outside Illinois so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IL (179 bridges here).
- Graham County, AZ · 179 bridges
- Thomas County, GA · 179 bridges
- Fremont County, IA · 179 bridges
- Morris County, KS · 179 bridges
Similar average build year
Nearest mean year-built outside IL (1979 here).
- Pima County, AZ · avg 1979 · 1,150 bridges
- Jefferson County, KY · avg 1979 · 662 bridges
- Spartanburg County, SC · avg 1979 · 638 bridges
- McPherson County, KS · avg 1979 · 586 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (93)
MIDDLE CRK RD-TR 1
FairOver: BR. OF MIDDLE CREEK
7 MI. SE OF LANARK, Carroll, IL
Built 1990 Load: 32.4 t ADT: 100
SHANNON RTE
FairOver: MIDDLE CREEK
3 MI. S. US52/IL64, Carroll, IL
Built 1998 Load: 32.4 t ADT: 175
W FAIRHAVEN ROAD
FairOver: JOHNSON CREEK
1.5 M SE THOMPSON, Carroll, IL
Built 1981 Load: 32.4 t ADT: 75
THOMSON RD
FairOver: LITTLE ROCK CREEK
5 MI SW CHADWICK, Carroll, IL
Built 1932 Load: 32.4 t ADT: 50
E FAIRHAVEN ROAD
FairOver: BR LITTLE ROCK CREEK
5.5 MI SW CHADWICK, Carroll, IL
Built 1983 Load: 32.4 t ADT: 100
SOUTH OTTER CREEK
FairOver: OTTER CREEK
4 MI N MILLEDGEVILLE, Carroll, IL
Built 1959 Load: 32.4 t ADT: 50
SOUTH CENTER DRIVE
FairOver: OTTER CREEK
4 MILES E CHADWICK, Carroll, IL
Built 1962 Load: 32.4 t ADT: 50
E LIVINGGOOD ROAD
FairOver: ROCK CREEK
3 MI SE CHADWICK, Carroll, IL
Built 1979 Load: 32.4 t ADT: 75
GOOSE ROAD
FairOver: GOOSE CREEK
4 MI SE MILLEDGEVILL, Carroll, IL
Built 1977 Load: 32.4 t ADT: 75
S GRANDVIEW ROAD
FairOver: EAGLE CREEK
5 M NE MILLEDGEVILLE, Carroll, IL
Built 1977 Load: 32.4 t ADT: 25
SUNSHINE ROAD
FairOver: ELKHORN CREEK
3 M SE MILLEDGEVILLE, Carroll, IL
Built 1987 Load: 32.4 t ADT: 200
ILL 64 AND US 52
FairOver: STRADDLE CREEK
3.4 MI E JCT ILL 78, Carroll, IL
Built 1952 Load: 32.7 t ADT: 2,950
ILL 78
FairOver: JOHNSON CREEK
0.5 MI S JCT ILL 40, Carroll, IL
Built 1984 Load: 33.4 t ADT: 1,700
US 52 & IL 64
FairOver: BR. OF SRADDLE CREEK
3.1 MI. E. OF LANARK, Carroll, IL
Built 2000 Load: 34.0 t ADT: 2,500
TEMPEL RD
FairOver: N BRANCH LOST CREEK
3 MI NE SHANNON, Carroll, IL
Built 1978 Load: 34.0 t ADT: 50
ILL 84 (FAP 308)
FairOver: RUSH CREEK
3.1 MI S JO DAV CO, Carroll, IL
Built 1927 Load: 34.3 t ADT: 1,400
S WAGNER ROAD
FairOver: OTTER CREEK
3 MI SW MILLEDGEVILL, Carroll, IL
Built 1988 Load: 34.3 t ADT: 25
ILL 84
FairOver: PLUM RIVER
1.0 MI S JCT ILL 64, Carroll, IL
Built 1978 Load: 34.7 t ADT: 4,200
BIG CUT ROAD
FairOver: JOHNSON CREEK
0.3 MI NW ARGO FAY, Carroll, IL
Built 1978 Load: 35.0 t ADT: 125
ILL 73
FairOver: STREAM
0.6 MI S STEPH CO, Carroll, IL
Built 1932 Load: 35.6 t ADT: 2,150
TR-83 E Townline R
FairOver: STRADDLE CREEK
1.0 M W OF LANARK, Carroll, IL
Built 1985 Load: 36.0 t ADT: 100
IDEAL ROAD
FairOver: ROCK CREEK
3 MI W MILLEDGEVILLE, Carroll, IL
Built 1974 Load: 36.3 t ADT: 450
ARGO FAY ROAD
FairOver: JOHNSON CREEK
1.9 MI E OF ILL 84, Carroll, IL
Built 1987 Load: 36.9 t ADT: 2,350
ILL 40
FairOver: JOHNSON CREEK
1.5 MI E OF ILL 78, Carroll, IL
Built 1984 Load: 37.3 t ADT: 800
CRIM DR (ARMY DEPO
FairOver: APPLE RIVER
1.2 MI. W. OF IL 84, Carroll, IL
Built 1940 Load: 37.6 t ADT: 350
ILL 84
FairOver: DRAINAGE DITCH
2 MI N SAVANNA, Carroll, IL
Built 1929 Load: 37.9 t ADT: 1,500
ILL 73
FairOver: STRADDLE CREEK
0.2 MI N OF LANARK, Carroll, IL
Built 1989 Load: 37.9 t ADT: 3,350
US 52 & IL 64
FairOver: PLUM RIVER
0.6MI. E. OF IL 84, Carroll, IL
Built 1999 Load: 39.9 t ADT: 3,450
ILL 78
FairOver: SAND CREEK
N EDGE ARGO FAY RD, Carroll, IL
Built 1989 Load: 40.5 t ADT: 1,550
ILL 78
FairOver: TRIB E FORK PLUM RIV
4 MI N MT CARROLL, Carroll, IL
Built 1990 Load: 41.5 t ADT: 625
ARGO FAY ROAD
FairOver: JOHNSON CREEK TRIB.
2 MI. SW OF ARGO FAY, Carroll, IL
Built 1994 Load: 41.5 t ADT: 1,600
IL 78
FairOver: EAST JOHNSON CREEK
4 MI. S. MT CARROLL, Carroll, IL
Built 1996 Load: 41.8 t ADT: 1,550
ILL 78
FairOver: N BRANCH SAND CREEK
0.1 MI N ARGO FAY RD, Carroll, IL
Built 1989 Load: 42.4 t ADT: 1,550
ARGO FAY ROAD
FairOver: SAND CREEK TRIB.
1 MI W OF ILL 78, Carroll, IL
Built 1985 Load: 42.4 t ADT: 1,450
IL 84
FairOver: BNSF RR
.3 MI S IL64 SAVANNA, Carroll, IL
Built 1988 Load: 43.1 t ADT: 5,550
ARGO FAY ROAD
FairOver: UNNAMED STREAM
2.5 MI. E. THOMSON, Carroll, IL
Built 1994 Load: 43.4 t ADT: 1,950
IL 40
FairOver: ROCK CREEK
2 MI. E. OF CHADWICK, Carroll, IL
Built 1995 Load: 44.1 t ADT: 950
IL 84
FairOver: SOO LINE RR/CITY ST
.1 MI S IL64 SAVANNA, Carroll, IL
Built 1988 Load: 44.4 t ADT: 5,550
ILL 78
FairOver: CARROLL CREEK
1.1 MI N JCT ILL 64, Carroll, IL
Built 2002 Load: 45.0 t ADT: 1,900
IL 78
FairOver: EAST PLUM RIVER
3 MI. N. MT CARROLL, Carroll, IL
Built 1995 Load: 46.0 t ADT: 625
IL 40
FairOver: OTTER CREEK
1.3 MI W MILLEDGVILL, Carroll, IL
Built 2015 Load: 48.3 t ADT: 1,850
US 52 & ILL 64
FairOver: CARROLL CREEK
1.7 MI E OF ILL 78, Carroll, IL
Built 2014 Load: 76.5 t ADT: 2,950
ILL 78
FairOver: BNSF RR
2 MI N ARGO FAY RD, Carroll, IL
Built 1949 Load: 86.2 t ADT: 1,550
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.