Total bridges
319
Public highway bridges in Adams County
County profile · official public datasets
Adams County, IL
319 public highway bridges tracked in the FHWA National Bridge Inventory: 40.4% rated Good, 53.6% Fair, 6% Poor.
- 319
- Public bridges
- 40.4%
- Good condition
- 6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Adams County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 24%
- lowest Poor share in state
- 6%
- Poor-condition share
- 319
- public highway bridges
- 1976
- 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.
Adams County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Adams County ranks #24 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6%). Adams County, Illinois contains 319 public highway bridges. Roughly 40.4% are rated “Good,” 53.6% “Fair,” and 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
40.4%
129 of 319 rated 7-9
Fair condition
53.6%
171 of 319 rated 5-6
Poor condition
6%
19 of 319 rated 4 or below
In-state Poor-share rank
#24 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 319 NBI-tracked bridges by lowest applicable component rating.
Good 40.4% (129)
Fair 53.6% (171)
Poor 6% (19)
Adams County's Poor-condition bridges carry 28,035 vehicle crossings a day
That is 7.3% of the county's reported daily bridge traffic on 6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 1,476 crossings a day against 1,139 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 319 of 319 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
27.9% of Adams County's bridges have passed the 50-year mark
89 of the 319 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 40.4% 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 26.8% of the county's Poor-condition bridge traffic
HARRISON STREET over CURTIS CREEK, built 1967, carries 7,500 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 28,035 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Adams County's bridges were built
319 bridges with a recorded construction year, grouped by decade
- pre-1900 3
Built before 1900
3 bridges
- 1900s 24
1900–1909
24 bridges
- 1910s 3
1910–1919
3 bridges
- 1920s 9
1920–1929
9 bridges
- 1930s 10
1930–1939
10 bridges
- 1940s 3
1940–1949
3 bridges
- 1950s 8
1950–1959
8 bridges
- 1960s 18
1960–1969
18 bridges
- 1970s
1970–1979
42 bridges
- 1980s
1980–1989
86 bridges
- 1990s
1990–1999
58 bridges
- 2000s 31
2000–2009
31 bridges
- 2010s 18
2010–2019
18 bridges
- 2020s 6
2020–2029
6 bridges
What this shows Construction peaked in the 1980s, when 86 of the county's bridges still in the inventory were built, which is 27% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1976) matches the Illinois average (1979).
How Adams County compares with Illinois's closest counties by inventory size
The 5 Illinois counties nearest Adams County in number of bridges, with their condition splits. Its 6% Poor share is the 2nd-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1978 is in line with the group.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Pike County | 330 | 23.9% | 66.1% | 10% | 1979 |
| Henry County | 328 | 49.4% | 39.6% | 11% | 1978 |
| Christian County | 321 | 16.2% | 67% | 16.8% | 1969 |
| Adams County (this page) | 319 | 40.4% | 53.6% | 6% | 1976 |
| Franklin County | 310 | 77.1% | 20.3% | 2.6% | 1983 |
| Coles County | 304 | 39.5% | 51.6% | 8.9% | 1981 |
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 Adams 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 Adams County, both outside Illinois so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IL (319 bridges here).
- Garland County, AR · 319 bridges
- Mesa County, CO · 319 bridges
- Bates County, MO · 319 bridges
- Clermont County, OH · 319 bridges
Similar average build year
Nearest mean year-built outside IL (1976 here).
- Marion County, IN · avg 1976 · 958 bridges
- Mohave County, AZ · avg 1976 · 641 bridges
- Comanche County, OK · avg 1976 · 593 bridges
- Prince George's County, MD · avg 1976 · 576 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (319)
TR 601
FairOver: PIGEON CREEK
4.4 MI E FALL CREEK, Adams, IL
Built 1987 Load: 32.4 t ADT: 25
TR 175
FairOver: URSA CREEK
1.4M SW URSA, Adams, IL
Built 1988 Load: 32.4 t ADT: 50
TR 488
FairOver: WALNUT FORK
1.9 MI NW KELLERVILL, Adams, IL
Built 1988 Load: 32.4 t ADT: 100
TR 40
FairOver: BUEL BRANCH
1.0 MI W LIMA, Adams, IL
Built 1987 Load: 32.4 t ADT: 100
TR 471A
FairOver: TOUR MEAL CREEK
2.8 MI W LIBERTY, Adams, IL
Built 1989 Load: 32.4 t ADT: 75
TR 162
FairOver: FALL CREEK
1.2 MI E FALL CREEK, Adams, IL
Built 1989 Load: 32.4 t ADT: 75
TR 309
FairOver: MCKEE CREEK
3.1MI SE COLUMBUS, Adams, IL
Built 1990 Load: 32.4 t ADT: 125
TR 488
FairOver: WALNUT FORK
2.7MI NW KELLERVILLE, Adams, IL
Built 1990 Load: 32.4 t ADT: 100
TR 496
FairOver: BR CEDAR CREEK
1 MI E LA PRARIE, Adams, IL
Built 1991 Load: 32.4 t ADT: 50
TR 103A
FairOver: JENKINS CREEK
2.0 MI W MARCELLINE, Adams, IL
Built 1991 Load: 32.4 t ADT: 75
TR 89
FairOver: BALDWIN BRANCH
2.2MI NE MENDON, Adams, IL
Built 1993 Load: 32.4 t ADT: 125
TR 184
FairOver: MILL CREEK
2.0 MI S FOWLER, Adams, IL
Built 1991 Load: 32.4 t ADT: 100
TR 130
FairOver: MILL CREEK
1.6 MI SE QUINCY, Adams, IL
Built 1992 Load: 32.4 t ADT: 200
TR 175
FairOver: INDIAN GRAVE DITCH
3.5MI SW URSA, Adams, IL
Built 1994 Load: 32.4 t ADT: 50
TR 87
FairOver: SOUTH FORK CREEK
4 MI E GOLDEN, Adams, IL
Built 1997 Load: 32.4 t ADT: 25
TR 315
FairOver: CURL CREEK
4.25MI SW CLAYTON, Adams, IL
Built 1997 Load: 32.4 t ADT: 50
RIDGEWOOD DR
FairOver: CURTIS CREEK
CITY OF QUINCY, Adams, IL
Built 1981 Load: 32.4 t ADT: 100
N 18TH ST
FairOver: CEDAR CREEK
N 18TH ST, Adams, IL
Built 2002 Load: 32.4 t ADT: 3,150
QUINSIPPI ISLAND R
FairOver: QUINCY BAY
SE SEC34 T15 R9W, Adams, IL
Built 2013 Load: 32.4 t ADT: 200
US 24
FairOver: HOMAN CREEK
.05M N 12TH ST., Adams, IL
Built 1968 Load: 32.7 t ADT: 3,800
CH 3
FairOver: CREEK
6.5 MI NE OF QUINCY, Adams, IL
Built 1940 Load: 32.7 t ADT: 325
IL 57
FairOver: HARKNESS CREEK
AT BLUFF HALL, Adams, IL
Built 1941 Load: 33.4 t ADT: 4,150
ILL 96
FairOver: FAI 172
I-72/IL96 INT, Adams, IL
Built 1976 Load: 33.4 t ADT: 3,050
CH 8
FairOver: JENKINS CREEK
1.4 MI. W MARCELLINE, Adams, IL
Built 1900 Load: 33.4 t ADT: 150
FAP-733 (IL-61&94)
FairOver: Big Neck Creek
0.5M N IL-61&94 Jct., Adams, IL
Built 1924 Load: 33.7 t ADT: 700
FAS 1604/TR 349
FairOver: FAI 172
1.3MI N I172/IL104, Adams, IL
Built 1976 Load: 34.3 t ADT: 4,900
CH 21
FairOver: CURTIS CREEK
S CITY LIMITS QUINCY, Adams, IL
Built 1954 Load: 34.3 t ADT: 4,950
IL 96
FairOver: ROCK CREEK
2M S IL 61 IN URSA, Adams, IL
Built 1971 Load: 35.0 t ADT: 4,300
TR 0300
FairOver: TOURMEAL CRK
2.0 MI W LIBERTY, Adams, IL
Built 1900 Load: 35.0 t ADT: 150
TR 0440
FairOver: BEAR CREEK
1.6 MI S GOLDEN, Adams, IL
Built 1972 Load: 35.0 t ADT: 75
CH 12
FairOver: MCKEE CREEK
2.5 MI S COLUMBUS, Adams, IL
Built 1931 Load: 35.0 t ADT: 725
TR-190
FairOver: Sand Brook
1702N;1225E (N US24), Adams, IL
Built 1921 Load: 36.6 t ADT: 50
FAI 172 NB
FairOver: ILL 57
I-172/IL57 INT, Adams, IL
Built 1982 Load: 36.6 t ADT: 6,550
TR 72
FairOver: JENKINS CREEK
2.0 MI. N. E. VRSA, Adams, IL
Built 1983 Load: 36.9 t ADT: 100
CH 48
FairOver: LIERLE CREEK
4.0 MI N LIBERTY, Adams, IL
Built 1959 Load: 37.3 t ADT: 1,300
TR 164
FairOver: BEAR CREEK
3.75 MI W LORAINE, Adams, IL
Built 1985 Load: 37.3 t ADT: 50
TR 0116
FairOver: MILL CREEK
3.0 MI SE QUINCY, Adams, IL
Built 1900 Load: 37.6 t ADT: 400
TR 105
FairOver: CREEK
1 MI N MENDON, Adams, IL
Built 1994 Load: 37.6 t ADT: 150
TR 304
FairOver: BRUSHY CREEK
2MI N COATSBURG, Adams, IL
Built 1994 Load: 37.6 t ADT: 75
CH 11
FairOver: LIERLE BRANCH
4.6 MI N OF LIBERTY, Adams, IL
Built 1983 Load: 37.9 t ADT: 675
TR 314
FairOver: THURMAN CRK
3.0 E OF LORAINE, Adams, IL
Built 1983 Load: 38.2 t ADT: 75
IL 61
FairOver: BIG NECK CREEK
1.1M W IL 94, Adams, IL
Built 1996 Load: 38.6 t ADT: 850
TR 118
FairOver: URSA CREEK
1.5 MI W MENDON, Adams, IL
Built 1985 Load: 38.6 t ADT: 125
OR 79
FairOver: FAI 172
2.2MI S I172/IL57, Adams, IL
Built 1990 Load: 38.9 t ADT: 575
IL 336/61 (SB)
FairOver: S FORK BEAR CREEK
.6M SE JCT IL 61 E, Adams, IL
Built 1999 Load: 38.9 t ADT: 5,150
IL 336/61 (NB)
FairOver: S FORK BEAR CREEK
.6M SE JCT IL 61 E, Adams, IL
Built 1999 Load: 38.9 t ADT: 5,150
FAU 7823/N 12TH ST
FairOver: CEDAR CREEK
1.9MI S IL24 ON 12TH, Adams, IL
Built 1995 Load: 39.5 t ADT: 6,300
CH 51
FairOver: FALL CREEK
1.0 NE FALL CREEK, Adams, IL
Built 1948 Load: 39.9 t ADT: 500
TR 551
FairOver: FAI 172
2 MI S I172/IL96, Adams, IL
Built 1981 Load: 40.5 t ADT: 75
US 24(WB)/ BROADWA
FairOver: MISS. R/STREETS/BNRR
W EDGE DWNTWN QUINCY, Adams, IL
Built 1986 Load: 40.5 t ADT: 8,600
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.