Total bridges
346
Public highway bridges in Macon County
County profile · official public datasets
Macon County, IL
346 public highway bridges tracked in the FHWA National Bridge Inventory: 25.7% rated Good, 58.7% Fair, 15.6% Poor.
- 346
- Public bridges
- 25.7%
- Good condition
- 15.6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Macon County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- 93rd
- of 102 on Poor share
- 15.6%
- Poor-condition share
- 346
- public highway bridges
- 1984
- 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.
Macon County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Macon County ranks #93 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.6%). Macon County, Illinois contains 346 public highway bridges. Roughly 25.7% are rated “Good,” 58.7% “Fair,” and 15.6% “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
25.7%
89 of 346 rated 7-9
Fair condition
58.7%
203 of 346 rated 5-6
Poor condition
15.6%
54 of 346 rated 4 or below
In-state Poor-share rank
#93 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 346 NBI-tracked bridges by lowest applicable component rating.
Good 25.7% (89)
Fair 58.7% (203)
Poor 15.6% (54)
Macon County's Poor-condition bridges carry 81,150 vehicle crossings a day
That is 9.4% of the county's reported daily bridge traffic on 15.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,503 crossings a day against 1,358 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 346 of 346 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
19.7% of Macon County's bridges have passed the 50-year mark
68 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 25.7% 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 25.8% of the county's Poor-condition bridge traffic
US 36(FAP 320) over LAKE SHORE DR(U 7390, built 1954, carries 20,900 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 54-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 81,150 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Macon County's bridges were built
346 bridges with a recorded construction year, grouped by decade
- 1900s 9
1900–1909
9 bridges
- 1920s 7
1920–1929
7 bridges
- 1930s 2
1930–1939
2 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 7
1950–1959
7 bridges
- 1960s 27
1960–1969
27 bridges
- 1970s
1970–1979
87 bridges
- 1980s
1980–1989
75 bridges
- 1990s
1990–1999
38 bridges
- 2000s
2000–2009
48 bridges
- 2010s 34
2010–2019
34 bridges
- 2020s 10
2020–2029
10 bridges
What this shows Construction peaked in the 1970s, when 87 of the county's bridges still in the inventory were built, which is 25.1% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1984, 5 years newer than the Illinois average of 1979.
How Macon County compares with Illinois's closest counties by inventory size
The 5 Illinois counties nearest Macon County in number of bridges, with their condition splits. Its 15.6% Poor share is the 5th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1983 is in line with the group.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Peoria County | 352 | 24.1% | 57.7% | 18.2% | 1983 |
| Macon County (this page) | 346 | 25.7% | 58.7% | 15.6% | 1984 |
| DuPage County | 344 | 37.5% | 54.4% | 8.1% | 1985 |
| Kankakee County | 344 | 40.1% | 53.5% | 6.4% | 1982 |
| Stephenson County | 342 | 61.1% | 36.3% | 2.6% | 1977 |
| Kane County | 336 | 48.2% | 45.5% | 6.3% | 1986 |
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 Macon 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 Macon County, both outside Illinois so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IL (346 bridges here).
- Dubuque County, IA · 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 IL (1984 here).
- Hennepin County, MN · avg 1984 · 936 bridges
- Duval County, FL · avg 1984 · 831 bridges
- El Paso County, CO · avg 1984 · 686 bridges
- Bell County, TX · avg 1984 · 660 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (346)
CH 36(Baker Rd)
FairOver: Dry Creek
1.8 Mi. SW of Macon, Macon, IL
Built 2016 Load: 32.4 t ADT: 100
FAS 546(CH 21)
FairOver: ILLINI DRAIN DITCH
1 MI E HEMAN, Macon, IL
Built 1980 Load: 32.4 t ADT: 425
TR 65A
FairOver: STREAM
2 MI N OF OAKLEY, Macon, IL
Built 1992 Load: 32.4 t ADT: 125
TR 1A(LAKE FORK RD
FairOver: STREAM
5.3 MI NW OF ARGENTA, Macon, IL
Built 1991 Load: 32.4 t ADT: 75
TR 263
FairOver: FINLEY CREEK
5 MI E OF MACON, Macon, IL
Built 1993 Load: 32.4 t ADT: 50
FAU 7355 – CH 24
FairOver: Lake Decatur Trib
4.3 Miles North East, Macon, IL
Built 1986 Load: 32.4 t ADT: 2,200
GARFIELD AV(FAU 73
FairOver: IC RR
0.50 MI E OF US 51, Macon, IL
Built 1958 Load: 32.4 t ADT: 7,950
SEIBERLINGST(MS170
FairOver: MOSQUITO CREEK
E EDGE OF BLUE MOUND, Macon, IL
Built 1982 Load: 32.4 t ADT: 575
FAU 7437(ML KING D
FairOver: SPRING CREEK
N NE OF DECATUR, Macon, IL
Built 1994 Load: 32.4 t ADT: 7,100
BALTIMORE FAU7449
FairOver: BIG CREEK
1 MI N MT ZION, Macon, IL
Built 2012 Load: 32.4 t ADT: 6,750
TR 939-PARK DR
FairOver: STEVENS CREEK
FAIRVIEW PARK, Macon, IL
Built 2012 Load: 32.4 t ADT: 400
US 51 NB (FAP 710)
FairOver: LAKE DECATUR
IN DECATUR, Macon, IL
Built 1962 Load: 33.0 t ADT: 22,400
US 51 SB (FAP 710)
FairOver: LAKE DECATUR
IN DECATUR, Macon, IL
Built 1971 Load: 34.0 t ADT: 22,400
FAP 322(SB) (US 51
FairOver: BS-51 & DECATUR CENTRALR
1 MI S OF DECATUR, Macon, IL
Built 1976 Load: 34.0 t ADT: 2,700
CH 55(FAS 644)
FairOver: I-72
1 MI S OF NIANTIC, Macon, IL
Built 1976 Load: 34.7 t ADT: 625
TR 45(KIRBY RD)
FairOver: I-72
NE OF DECATUR, Macon, IL
Built 1975 Load: 34.7 t ADT: 650
FAP 322(NB) (US 5
FairOver: BS-51 & DECATUR CENTRALR
1 MI S OF DECATUR, Macon, IL
Built 1976 Load: 34.7 t ADT: 2,700
N MONROE ST(FAU743
FairOver: SPRING CREEK
N SIDE OF DECATUR, Macon, IL
Built 1969 Load: 34.7 t ADT: 8,650
TR 263(RIDLEN RD)
FairOver: WILLOW BRANCH
1.2 MI SE MACON, Macon, IL
Built 1976 Load: 34.7 t ADT: 350
I-72 (EB)
FairOver: FAP 323 WB(US 36)
IN HARRISTOWN, Macon, IL
Built 1976 Load: 35.3 t ADT: 4,275
W MAIN ST (FAU 738
FairOver: STEVENS CREEK
W EDGE OF DECATUR, Macon, IL
Built 1988 Load: 35.3 t ADT: 2,300
TR 259A(BETHEL RD)
FairOver: MOSQUITO CREEK
3 MI NE BLUE MOUND, Macon, IL
Built 1980 Load: 35.3 t ADT: 35
CH 41(WYCKLES RD)
FairOver: LAKE FORK CREEK
3 MI NE WARRENSBURG, Macon, IL
Built 1985 Load: 35.3 t ADT: 75
CH 27(FAS 551)
FairOver: I-72
1 MI SW HARRISTOWN, Macon, IL
Built 1976 Load: 35.6 t ADT: 300
IL 48(FAU 7429)
FairOver: SANGAMON RIVER
0.5 MI N. OF ILL-105, Macon, IL
Built 1929 Load: 36.0 t ADT: 8,850
I-72(WB) & US 51(S
FairOver: FAU 7381
N EDGE HARRISTOWN, Macon, IL
Built 1976 Load: 36.0 t ADT: 7,000
I-72(EB) & US 51(N
FairOver: FAU 7381(HARSTWN BLV
N EDGE HARRISTOWN, Macon, IL
Built 1976 Load: 36.0 t ADT: 7,000
FAS 542 (SBI 2)
FairOver: LAKE FORK CREEK
.5 MI N OF MAROA, Macon, IL
Built 1980 Load: 36.0 t ADT: 675
TR 15A(MILLER RD)
FairOver: STREAM
1.5 MI NE ARGENTA, Macon, IL
Built 1984 Load: 36.0 t ADT: 75
FAU 7354(PERSHING
FairOver: SPRING CREEK
0.8 MI S BEARSDALE, Macon, IL
Built 2004 Load: 36.0 t ADT: 1,000
I-72 (WB)
FairOver: TR 117 NS RR
1 MI N HARRISTOWN, Macon, IL
Built 1976 Load: 36.6 t ADT: 7,000
FAU 7354 S.ELIZABE
FairOver: I-72
.5 MI S ILL-121 INT, Macon, IL
Built 1976 Load: 36.6 t ADT: 1,000
TR 30(STRAWN RD)
FairOver: DITCH
IL 121, Macon, IL
Built 1909 Load: 36.6 t ADT: 25
I-72 (EB)
FairOver: TR 117 NS RR
1 MI N HARRISTOWN, Macon, IL
Built 1976 Load: 36.9 t ADT: 7,000
I-72 (EB)
FairOver: FAS1536 DECATUR CENTRALR
1.5 MI NE ARGENTA, Macon, IL
Built 1975 Load: 36.9 t ADT: 5,950
I-72 (WB)
FairOver: FAS1536 DECATUR CENTRALR
1.5 MI NE ARGENTA, Macon, IL
Built 1975 Load: 36.9 t ADT: 5,950
FAP 320 (IL 121)
FairOver: SOUTH FORK CREEK
1.5 MI W OF HEMAN, Macon, IL
Built 1999 Load: 36.9 t ADT: 3,750
TR 45(KIRBY RD)
FairOver: STREAM
2 MI SE OREANA, Macon, IL
Built 1981 Load: 36.9 t ADT: 800
FAP 320(IL 121 & 4
FairOver: SPRING CREEK
IN DECATUR, Macon, IL
Built 1971 Load: 37.3 t ADT: 17,900
US51(SB)(FAP 322)
FairOver: STEVENS CREEK
3 MI N OF FORSYTH, Macon, IL
Built 1982 Load: 37.3 t ADT: 12,000
US51(NB)(FAP 322)
FairOver: STEVENS CREEK
3 MI N OF FORSYTH, Macon, IL
Built 1983 Load: 37.3 t ADT: 12,000
FAP 322(NB)(US 51)
FairOver: IL-48 & NS RR
.5 MI SW OF DECATUR, Macon, IL
Built 1978 Load: 37.6 t ADT: 5,900
TR 62(BANTAM RD)
FairOver: LAKE FORK CREEK
4.5 MI W MAROA, Macon, IL
Built 1976 Load: 37.6 t ADT: 50
FAP 322(NB) (US 5
FairOver: FAU 7426(TAYLOR RD)
1 MI S OF DECATUR, Macon, IL
Built 1976 Load: 37.9 t ADT: 4,400
FAP 322(SB) (US 5
FairOver: FAU 7426(TAYLOR RD)
1 MI S OF DECATUR, Macon, IL
Built 1976 Load: 37.9 t ADT: 4,400
MS 1800 C
FairOver: STREAM
W. BOILING SPRINGS, Macon, IL
Built 1982 Load: 37.9 t ADT: 550
IL 48(FAP 714)
FairOver: MOSQUITO CREEK
1.5 MI NE BLUE MOUND, Macon, IL
Built 1929 Load: 38.9 t ADT: 4,500
TR 150(GREENSWITCH
FairOver: I-72
1.83 MI S FAS 549, Macon, IL
Built 1972 Load: 38.9 t ADT: 3,300
I-72 (EB)
FairOver: FRIENDS CREEK
1 MI E OF ARGENTA, Macon, IL
Built 1975 Load: 38.9 t ADT: 5,950
I-72 (WB)
FairOver: FRIENDS CREEK
1 MI E OF ARGENTA, Macon, IL
Built 1975 Load: 38.9 t ADT: 5,950
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.