County profile · official public datasets

Whiteside County, IL

278 public highway bridges tracked in the FHWA National Bridge Inventory: 19.1% rated Good, 72.3% Fair, 8.6% Poor.

278
Public bridges
19.1%
Good condition
8.6%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Whiteside County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

64th
of 102 on Poor share
8.6%
Poor-condition share
278
public highway bridges
1977
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.

Whiteside County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Whiteside County ranks #64 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.6%). Whiteside County, Illinois contains 278 public highway bridges. Roughly 19.1% are rated “Good,” 72.3% “Fair,” and 8.6% “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.

Total bridges

278

Public highway bridges in Whiteside County

Good condition

19.1%

53 of 278 rated 7-9

Fair condition

72.3%

201 of 278 rated 5-6

Poor condition

8.6%

24 of 278 rated 4 or below

In-state Poor-share rank

#64 of 102

Among Illinois counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 278 NBI-tracked bridges by lowest applicable component rating.

Good
19.1% (53)
Fair
72.3% (201)
Poor
8.6% (24)

Whiteside County's Poor-condition bridges carry 10,995 vehicle crossings a day

That is 1.9% of the county's reported daily bridge traffic on 8.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 478 crossings a day against 2,893 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 277 of 278 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.1% of Whiteside County's bridges have passed the 50-year mark

131 of the 278 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 19.1% 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 16.4% of the county's Poor-condition bridge traffic

IL 78 over I-88, built 1974, carries 1,800 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 24-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 10,995 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Whiteside County's bridges were built

278 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 76 of the county's bridges still in the inventory were built, which is 27.3% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1977) matches the Illinois average (1979).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

How Whiteside County compares with Illinois's closest counties by inventory size

The 5 Illinois counties nearest Whiteside County in number of bridges, with their condition splits. Its 8.6% Poor share is the 3rd-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1981 is in line with the group.

Showing the 5 closest of 101 Illinois counties eligible for comparison.

Bridge inventory size and condition shares for Whiteside County and the 5 Illinois counties closest to it in inventory size
County Bridges Poor
Hancock County 292 20.2%
Edgar County 278 4%
Whiteside County (this page) 278 8.6%
Rock Island County 272 4.8%
Grundy County 269 26.8%
Wayne County 266 9%

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 Whiteside 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 Whiteside County, both outside Illinois so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IL (278 bridges here).

Similar average build year

Nearest mean year-built outside IL (1977 here).

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 278 Good 53 Fair 201 Poor 24

Good-condition bridges (53)

TR119 (PRAIR CTR R

Good

Over: DEER CREEK

6 MI W OF STERLING, Whiteside, IL

Built 1975 Load: 14.9 t ADT: 25

STROPES ROAD

Good

Over: DRAINAGE DITCH

4 MI NW ERIE, Whiteside, IL

Built 1971 Load: 19.4 t ADT: 100

PILGRIM RD

Good

Over: LITTLE SPRING CREEK

2 MI WEST OF COLETA, Whiteside, IL

Built 1961 Load: 20.7 t ADT: 525

ACKER ROAD

Good

Over: DRAINAGE DITCH

3 MI E. FULTON, Whiteside, IL

Built 1957 Load: 20.7 t ADT: 150

BLACK RD

Good

Over: DRAINAGE DITCH

5 MI SW OF MORRISON, Whiteside, IL

Built 1965 Load: 21.4 t ADT: 725

RUSH ROAD

Good

Over: BR OF ROCK RIVER

3 MI NE OF LYNDON, Whiteside, IL

Built 1974 Load: 21.4 t ADT: 50

BENSON RD

Good

Over: REEDY CREEK

1 MI SO OF ALBANY, Whiteside, IL

Built 1975 Load: 23.0 t ADT: 50

YATES ROAD

Good

Over: WINNEBAGO DITCH

8 MI S. ROCK FALLS, Whiteside, IL

Built 1955 Load: 26.6 t ADT: 150

COUNTY LINE ROAD

Good

Over: COUNTY DITCH

3 MI SE DEER GROVE, Whiteside, IL

Built 1966 Load: 27.5 t ADT: 75

CH 21 SAND RD

Good

Over: I-88 & STREAM

2.5 MI. NW. ERIE, Whiteside, IL

Built 1975 Load: 28.5 t ADT: 400

US 30

Good

Over: STREAM

3.6 MI W ROCK FALLS, Whiteside, IL

Built 1940 Load: 32.4 t ADT: 5,300

BEACH ROAD

Good

Over: TRIB. ROCK CREEK

3.5 MI N OF MORRISON, Whiteside, IL

Built 2006 Load: 32.4 t ADT: 25

MELLOTTS ROAD

Good

Over: LYNN CREEK

3.2 MI NW OF FENTON, Whiteside, IL

Built 1989 Load: 32.4 t ADT: 50

TR 42/CHASE RD

Good

Over: BR COUNTY DITCH

2 MI SE OF FULTON, Whiteside, IL

Built 2015 Load: 32.4 t ADT: 625

OSAGE ROAD

Good

Over: DRAINAGE DITCH

2 M SW DEER GROVE, Whiteside, IL

Built 1983 Load: 32.4 t ADT: 75

TR-141 (Matthew Rd

Good

Over: Deer Creek

7 MI W OF ROCKFALLS, Whiteside, IL

Built 2016 Load: 32.4 t ADT: 150

KEELEY RD

Good

Over: BR OF COUNTY DITCH

4 MI NW OF ERIE, Whiteside, IL

Built 2013 Load: 32.4 t ADT: 25

AVENUE F

Good

Over: UNNAMED CREEK

0.2 M S OF ST MARYS, Whiteside, IL

Built 1981 Load: 32.4 t ADT: 150

ST MARYS ROAD

Good

Over: UNNAMED CREEK

0.1 M W OF IL RT 40, Whiteside, IL

Built 1979 Load: 32.4 t ADT: 1,550

WILLOW CREEK RD

Good

Over: BR. OF ELKHORN CRK

4 MI N. OF STERLING, Whiteside, IL

Built 2004 Load: 32.4 t ADT: 50

ACKER RD

Good

Over: COTTONWOOD CREEK

3 MI E. OF FULTON, Whiteside, IL

Built 1996 Load: 32.4 t ADT: 150

PARK ROAD

Good

Over: COON CREEK

PROHETSTOWN ST. PARK, Whiteside, IL

Built 1995 Load: 32.4 t ADT: 400

DIXON AVENUE

Good

Over: I&M FEEDER CANAL

E EDGE ROCK FALLS, Whiteside, IL

Built 1965 Load: 33.7 t ADT: 5,500

COUNTY LINE ROAD

Good

Over: COUNTY DITCH

6.5 MI SSE ROCK FALL, Whiteside, IL

Built 1971 Load: 33.7 t ADT: 100

POLO ROAD

Good

Over: JORDAN CREEK

7 MI N. STERLING, Whiteside, IL

Built 1968 Load: 34.0 t ADT: 150

US 30

Good

Over: FRENCH CREEK

1 MI E OF MORRISON, Whiteside, IL

Built 1996 Load: 34.3 t ADT: 7,000

IL 78

Good

Over: FRENCH CREEK

S EDGE MORRISON, Whiteside, IL

Built 2015 Load: 34.7 t ADT: 2,150

IL 40

Good

Over: BRANCH DITCH

2.2 MI N DEER GROVE, Whiteside, IL

Built 1996 Load: 35.3 t ADT: 2,900

ARROW RD.

Good

Over: WINNEBEGO DITCH

0.5 MI W. DEER GROVE, Whiteside, IL

Built 1969 Load: 35.3 t ADT: 50

IL 40 LOCUST ST

Good

Over: STREAM

.1 MI S LYNN BLVD, Whiteside, IL

Built 1987 Load: 36.0 t ADT: 11,100

CORDOVA ROAD

Good

Over: DRAINAGE DITCH

3.7 MI WEST OF ERIE, Whiteside, IL

Built 2004 Load: 36.3 t ADT: 325

STROPES RD

Good

Over: MEREDOSIA DITCH

7 MI S ALBANY, Whiteside, IL

Built 2020 Load: 37.9 t ADT: 50

STAR RD

Good

Over: MEREDOSIA DITCH

2.5 MI NW ERIE, Whiteside, IL

Built 1969 Load: 38.2 t ADT: 10

IL 40

Good

Over: ROCK RIVER

STERLING & ROCK FALL, Whiteside, IL

Built 2012 Load: 39.2 t ADT: 19,800

CORDOVA ROAD

Good

Over: DRAINAGE DITCH

4 MI WEST OF ERIE, Whiteside, IL

Built 2004 Load: 39.5 t ADT: 325

AVENUE G

Good

Over: BN RR & WALLACE ST

STERLING, Whiteside, IL

Built 1963 Load: 39.9 t ADT: 7,700

I-88 EB

Good

Over: HOWLAND CREEK

.2 MI W LEE CO LINE, Whiteside, IL

Built 1972 Load: 39.9 t ADT: 7,850

US 30

Good

Over: DEER CREEK

5.5 MI. E. MORRISON, Whiteside, IL

Built 2000 Load: 40.5 t ADT: 6,100

AVENUE G

Good

Over: UP RR

STERLING, Whiteside, IL

Built 1963 Load: 41.1 t ADT: 7,700

MOLINE RD

Good

Over: DEER CREEK

3 MI SW I-88, Whiteside, IL

Built 1952 Load: 42.8 t ADT: 1,400

FREEPORT RD

Good

Over: PENROSE CREEK

.06MI S.PENROSE RD, Whiteside, IL

Built 1999 Load: 44.7 t ADT: 1,800

MOLINE ROAD

Good

Over: DRAINAGE DITCH

0.06 MI E WILMOT RD, Whiteside, IL

Built 2002 Load: 46.3 t ADT: 1,000

IL 40

Good

Over: DRAINAGE DITCH

0.5 MI. S. OF I-88, Whiteside, IL

Built 1993 Load: 47.6 t ADT: 6,000

BLACK RD

Good

Over: ROCK CREEK

5 SW OF MORRISON, Whiteside, IL

Built 2018 Load: 50.9 t ADT: 725

IL 172

Good

Over: BRANCH DITCH

2 MI. N. OF TAMPICO, Whiteside, IL

Built 1994 Load: 51.5 t ADT: 950

I-88

Good

Over: DITCH

2.5 MI W ERIE, Whiteside, IL

Built 1975 Load: 52.8 t ADT: 12,500

TR98 (MILLARD RD)

Good

Over: SPRING BROOK

4.5 MI E FULTON, Whiteside, IL

Built 2020 Load: 53.5 t ADT: 100

TR153 BENSON RD

Good

Over: TRIB TO SPRING CREEK

400 FT W KENNEDY RD, Whiteside, IL

Built 2022 Load: 56.7 t ADT: 50

US ROUTE 30

Good

Over: FRENCH CRK. TRIB.

3/4 MI E. MORRISON, Whiteside, IL

Built 2008 Load: 66.4 t ADT: 7,000

RIDGE ROAD

Good

Over: COUNTY DITCH NO ONE

6 MI. SW. ROCK FALLS, Whiteside, IL

Built 1977 Load: 83.3 t ADT: 150

Read our methodology - how this data is sourced, computed, and verified.

Related

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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.