Total bridges
528
Public highway bridges in LaSalle County
County profile · official public datasets
LaSalle County, IL
528 public highway bridges tracked in the FHWA National Bridge Inventory: 39.4% rated Good, 48.3% Fair, 12.3% Poor.
- 528
- Public bridges
- 39.4%
- Good condition
- 12.3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
LaSalle County posts a higher-than-median Poor-condition share among rated counties in the state across large county bridge inventory.
- 84th
- of 102 on Poor share
- 12.3%
- Poor-condition share
- 528
- public highway bridges
- 1978
- 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.
LaSalle County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, LaSalle County ranks #84 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.3%). LaSalle County, Illinois contains 528 public highway bridges. Roughly 39.4% are rated “Good,” 48.3% “Fair,” and 12.3% “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
39.4%
208 of 528 rated 7-9
Fair condition
48.3%
255 of 528 rated 5-6
Poor condition
12.3%
65 of 528 rated 4 or below
In-state Poor-share rank
#84 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 528 NBI-tracked bridges by lowest applicable component rating.
Good 39.4% (208)
Fair 48.3% (255)
Poor 12.3% (65)
LaSalle County's Poor-condition bridges carry 81,630 vehicle crossings a day
That is 7.5% of the county's reported daily bridge traffic on 12.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,275 crossings a day against 2,002 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 525 of 528 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
39% of LaSalle County's bridges have passed the 50-year mark
206 of the 528 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 39.4% 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 13.1% of the county's Poor-condition bridge traffic
US 6 FAP 623 over FOX RIVER, built 1928, carries 10,700 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 65-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 81,630 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When LaSalle County's bridges were built
528 bridges with a recorded construction year, grouped by decade
- 1900s 2
1900–1909
2 bridges
- 1910s 3
1910–1919
3 bridges
- 1920s 12
1920–1929
12 bridges
- 1930s 36
1930–1939
36 bridges
- 1940s 14
1940–1949
14 bridges
- 1950s 31
1950–1959
31 bridges
- 1960s
1960–1969
76 bridges
- 1970s
1970–1979
74 bridges
- 1980s
1980–1989
112 bridges
- 1990s
1990–1999
64 bridges
- 2000s
2000–2009
49 bridges
- 2010s
2010–2019
49 bridges
- 2020s 6
2020–2029
6 bridges
What this shows Construction peaked in the 1980s, when 112 of the county's bridges still in the inventory were built, which is 21.2% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1978) matches the Illinois average (1979).
How LaSalle County compares with Illinois's closest counties by inventory size
The 5 Illinois counties nearest LaSalle County in number of bridges, with their condition splits. Its 12.3% Poor share is the 5th-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1979 is in line with the group.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Livingston County | 579 | 51.8% | 39.9% | 8.3% | 1978 |
| Iroquois County | 570 | 46.5% | 39.1% | 14.4% | 1980 |
| LaSalle County (this page) | 528 | 39.4% | 48.3% | 12.3% | 1978 |
| Madison County | 523 | 49.3% | 42.3% | 8.4% | 1979 |
| Vermilion County | 494 | 27.7% | 65% | 7.3% | 1979 |
| St. Clair County | 486 | 50% | 40.9% | 9.1% | 1977 |
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 LaSalle 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 LaSalle County, both outside Illinois so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IL (528 bridges here).
- Merced County, CA · 528 bridges
- Nueces County, TX · 528 bridges
- New Castle County, DE · 527 bridges
- Marathon County, WI · 530 bridges
Similar average build year
Nearest mean year-built outside IL (1978 here).
- Orange County, CA · avg 1978 · 1,164 bridges
- Sumner County, KS · avg 1978 · 659 bridges
- Allen County, IN · avg 1978 · 613 bridges
- Buncombe County, NC · avg 1978 · 555 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (255)
FAS 260 CH 13
FairOver: LITTLE VERMILION RV
E4TH N4051, LaSalle, IL
Built 1987 Load: 39.2 t ADT: 650
IL 23 NB IN STREAT
FairOver: INTER STREAM
14.30 MI S OF ILL 71, LaSalle, IL
Built 1965 Load: 39.5 t ADT: 8,000
ILL 23 FAP 68
FairOver: OTTER CR
2.8 MI N. OF ILL 18, LaSalle, IL
Built 1974 Load: 39.5 t ADT: 6,300
TR 322A
FairOver: OTTER CREEK
E 19TH N 1500, LaSalle, IL
Built 1934 Load: 39.9 t ADT: 275
FAU6046 CHAMPLAIN
FairOver: GOOSE CREEK
0.20 MI N OF US 6, LaSalle, IL
Built 1933 Load: 40.5 t ADT: 3,150
SHERIDAN ROAD
FairOver: MISSION CREEK
0.6 MI N OF US 52, LaSalle, IL
Built 1930 Load: 40.5 t ADT: 1,600
US 6 FAP 623
FairOver: I-39/US 51
2.74 MI E OF ILL 351, LaSalle, IL
Built 1986 Load: 40.5 t ADT: 9,050
TR 513
FairOver: I-39/US 51
2.0 MI N OF IL 18, LaSalle, IL
Built 1988 Load: 40.5 t ADT: 50
CH 19 FAS 270
FairOver: I-39/US 51
2.3 MI N. of US 52, LaSalle, IL
Built 1971 Load: 40.8 t ADT: 600
ILL 351 FAP 619
FairOver: LONE STAR CEMENT RR
2.55 MI S OF US 6, LaSalle, IL
Built 1995 Load: 40.8 t ADT: 3,400
TR 105
FairOver: I-39/US 51
1 MI S OF US 34, LaSalle, IL
Built 1977 Load: 41.5 t ADT: 225
CO RD 43
FairOver: TOMAHAWK CREEK
E 8TH N 3740, LaSalle, IL
Built 1933 Load: 41.5 t ADT: 500
US 6
FairOver: PECUMSAGAN CR
5.0 MI E OF ILL 251, LaSalle, IL
Built 1954 Load: 41.8 t ADT: 7,150
TWP RD TR 456
FairOver: FAI 80
3.9 MI E MARSEIL. RD, LaSalle, IL
Built 1960 Load: 41.8 t ADT: 75
FAU6046 E18TH RD
FairOver: FAI 80
1.0 MI E OF ILL 23, LaSalle, IL
Built 1959 Load: 42.1 t ADT: 2,100
I-39/US 51 SB
FairOver: BAILEY CREEK
0.49 MI S OF CH 54, LaSalle, IL
Built 1989 Load: 42.1 t ADT: 9,700
I-39/US 51 NB
FairOver: BAILEY CREEK
0.49 MI S OF CH 54, LaSalle, IL
Built 1989 Load: 42.1 t ADT: 9,700
I-39/US 51 SB
FairOver: Norfolk & Southern RR
1.48 MI N OF ILL 18, LaSalle, IL
Built 1988 Load: 42.4 t ADT: 9,700
I-39/US 51 NB
FairOver: Norfolk & Southern RR
1.48 MI N OF ILL 18, LaSalle, IL
Built 1988 Load: 42.4 t ADT: 9,700
US 6 W OF MARSEILL
FairOver: LONG CREEK
4.51 MI E OF ILL 71, LaSalle, IL
Built 1958 Load: 42.8 t ADT: 3,850
ILL 18 WB
FairOver: VERMILION RIVER
0.10 MI W OF ILL 23, LaSalle, IL
Built 1988 Load: 42.8 t ADT: 4,200
IL 170 FAP 786
FairOver: IL RIVER & RIVER RD
S OF US RT 6, LaSalle, IL
Built 2009 Load: 42.8 t ADT: 4,750
IL 71 FAP 311
FairOver: I-80
JUNCTION IL 71, LaSalle, IL
Built 1995 Load: 43.1 t ADT: 6,000
TR 324
FairOver: CREEK
E 1951ST N 3290, LaSalle, IL
Built 1930 Load: 43.1 t ADT: 50
TWP RD TR 434
FairOver: FAI 80
1.8 MI E MARSEIL RD, LaSalle, IL
Built 1960 Load: 43.4 t ADT: 75
TWP RD TR 448
FairOver: FAI 80
3 MI E MARSEILLES RD, LaSalle, IL
Built 1960 Load: 43.4 t ADT: 75
MS 6490 IN MENDOTA
FairOver: L. VERMILLION CR
E 4TH N 4345, LaSalle, IL
Built 1965 Load: 43.7 t ADT: 225
TWP RD TR 4
FairOver: FAI 80
9.12 MI W ILL 47, LaSalle, IL
Built 1960 Load: 44.1 t ADT: 50
CH 54
FairOver: I-39/US 51
0.54 W OF IL 251, LaSalle, IL
Built 1988 Load: 44.1 t
US 34 FAP 587
FairOver: SUTPHENS RUN
8.71 MI E OF ILL 251, LaSalle, IL
Built 1984 Load: 45.4 t ADT: 1,800
IL 23 FAP 68
FairOver: BUCK CREEK
3.0 MI S OF US 52, LaSalle, IL
Built 2012 Load: 45.4 t ADT: 3,350
IL 23/FAP 68
FairOver: I 80
ILL 23 AT OTTAWA, LaSalle, IL
Built 1993 Load: 46.0 t ADT: 16,500
ILL 351/FAP619
FairOver: IL RIVER
1.0 MI. S OF US 6, LaSalle, IL
Built 2003 Load: 46.0 t ADT: 5,250
ILL 71
FairOver: COVEL CR
7.38 MI E OF ILL 178, LaSalle, IL
Built 1981 Load: 46.3 t ADT: 1,650
US 6 FAP 623
FairOver: LITTLE VERMILION R
2.15 MI E OF IL 251, LaSalle, IL
Built 1966 Load: 47.3 t ADT: 9,050
FAS 254 CH 5
FairOver: I-39/US 51
4.0 MI N OF IL 18, LaSalle, IL
Built 1988 Load: 47.6 t ADT: 350
ILL 351 FAP 619
FairOver: LONE STAR CEMENT RR
2.0 MI S OF US 6, LaSalle, IL
Built 1939 Load: 48.3 t ADT: 4,250
MARSEILLES RD/FAS2
FairOver: I-80
3.8 MI E OF IL 71, LaSalle, IL
Built 2009 Load: 48.3 t ADT: 4,500
MS 6460 (E 6TH RD)
FairOver: FAI 80
4.4 MI E OF IL 251, LaSalle, IL
Built 1961 Load: 48.6 t ADT: 275
ILL 251 (SB)
FairOver: I 80
JC ILL 251 & I-80, LaSalle, IL
Built 1961 Load: 50.5 t ADT: 6,550
ILL 251 (NB)
FairOver: I 80
JCT IL 251 & I-80, LaSalle, IL
Built 1961 Load: 50.5 t ADT: 6,550
US RT 6
FairOver: WALBRIDGE CREEK
3.63 MI E OF ILL 71, LaSalle, IL
Built 1958 Load: 50.9 t ADT: 3,850
TR 322A
FairOver: WOLF CR
E 19TH N 1690, LaSalle, IL
Built 1954 Load: 53.1 t ADT: 275
I-39/US 51 SB
FairOver: SANDY CREEK
1.23 MI N OF ILL 18, LaSalle, IL
Built 1988 Load: 54.1 t ADT: 9,700
I-39/US 51 NB
FairOver: SANDY CREEK
1.22 MI N OF ILL 18, LaSalle, IL
Built 1988 Load: 54.1 t ADT: 9,700
FAI-80 EB
FairOver: B.N. RR
2.0 MI E OF ILL 23, LaSalle, IL
Built 1959 Load: 57.0 t ADT: 13,700
FAI-80 WB
FairOver: B.N. RR
2.0 MI E OF ILL 23, LaSalle, IL
Built 1959 Load: 57.0 t ADT: 13,700
CAMPGROUND ENTRANC
FairOver: PERSON CREEK
ILLINI PARK RD WEST, LaSalle, IL
Built 1995 Load: 57.3 t ADT: 325
CO RD 55
FairOver: PERSON CREEK
N 2653 E 2325, LaSalle, IL
Built 1934 Load: 57.7 t ADT: 1,300
TR 205
FairOver: BUCK CREEK
N 36TH E 1415, LaSalle, IL
Built 1934 Load: 64.2 t ADT: 50
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.