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

All bridges (278)

IL 78

Fair

Over: DRAINAGE DITCH

0.2 MI. N. OF US 30, Whiteside, IL

Built 1996 Load: 31.4 t ADT: 1,050

ERIE ROAD

Fair

Over: ROCK RIVER

1 MILE SOUTH OF ERIE, Whiteside, IL

Built 1955 Load: 32.1 t ADT: 1,200

CH 37 LYNDON RD

Fair

Over: I-88

.5 MI N LYNDON, Whiteside, IL

Built 1974 Load: 32.4 t ADT: 850

US 30

Fair

Over: CREEK

.30MI W PROPHET RD, Whiteside, IL

Built 1940 Load: 32.4 t ADT: 5,100

ILL 78

Fair

Over: STREAM

2.1 MI S MORRISON, Whiteside, IL

Built 1979 Load: 32.4 t ADT: 1,800

PILGRIM RD

Fair

Over: JORDAN CREEK

AT THE OGLE CO LN, Whiteside, IL

Built 1992 Load: 32.4 t ADT: 1,850

FAI 88

Fair

Over: STREAM

0.3 MI W YORKTOWN RD, Whiteside, IL

Built 1975 Load: 32.4 t ADT: 12,600

PILGRIM ROAD

Fair

Over: ELKHORN CREEK

6 MI NORTH STERLING, Whiteside, IL

Built 1935 Load: 32.4 t ADT: 650

MC CUE ROAD

Fair

Over: ELKHORN CREEK

2 MI WEST OF STERLIN, Whiteside, IL

Built 1961 Load: 32.4 t ADT: 1,350

EMERSON ROAD

Fair

Over: ELKHORN CREEK

EAST EDGE OF EMERSON, Whiteside, IL

Built 1982 Load: 32.4 t ADT: 4,150

EMERSON ROAD

Fair

Over: SPRING CREEK

W EDGE OF EMERSON, Whiteside, IL

Built 1982 Load: 32.4 t ADT: 4,150

EMERSON ROAD

Fair

Over: SUGAR CREEK

.5 MI W OF EMERSON, Whiteside, IL

Built 1982 Load: 32.4 t ADT: 3,050

MILL RD

Fair

Over: COON CREEK

1 MI E PROPHETSTOWN, Whiteside, IL

Built 1984 Load: 32.4 t ADT: 325

ALBANY ROAD

Fair

Over: MINERAL SPRINGS CRK.

2 MI NORTH OF ERIE, Whiteside, IL

Built 2007 Load: 32.4 t ADT: 1,400

ALBANY ROAD

Fair

Over: DRAINAGE DITCH

0.5 MI NORTH OF ERIE, Whiteside, IL

Built 2007 Load: 32.4 t ADT: 1,200

LYNDON ROAD

Fair

Over: FRENCH CREEK

0.7 MI N JCT US 30, Whiteside, IL

Built 2002 Load: 32.4 t ADT: 800

CREAMERY RD

Fair

Over: OTTER CREEK

.11MI N SPRNG VLY RD, Whiteside, IL

Built 2008 Load: 32.4 t ADT: 75

STAR ROAD-FAS 2192

Fair

Over: COON CREEK

0.88MI E JCT ILL 78, Whiteside, IL

Built 2010 Load: 32.4 t ADT: 2,550

LYNDON ROAD

Fair

Over: ROCK CREEK

3.5 MI NE MORRISON, Whiteside, IL

Built 2010 Load: 32.4 t ADT: 725

DEAN RD

Fair

Over: ROCK CREEK

4 MI NW OF COLETA, Whiteside, IL

Built 1986 Load: 32.4 t ADT: 50

ELM RD

Fair

Over: BRANCH OF ROCK CREEK

5 MI NE OF MORRISON, Whiteside, IL

Built 1986 Load: 32.4 t ADT: 50

SAWYER ROAD

Fair

Over: LITTLE ROCK CREEK

6 MI. N. MORRISON, Whiteside, IL

Built 1993 Load: 32.4 t ADT: 10

FELTON ROAD (TR 57

Fair

Over: ROCK CREEK

5 MI NE OF MORRISON, Whiteside, IL

Built 1992 Load: 32.4 t ADT: 50

CLARK RD

Fair

Over: BR OF LITTLE ROCK CR

8.0 M N OF MORRISON, Whiteside, IL

Built 1987 Load: 32.4 t ADT: 50

YORKTOWN ROAD

Fair

Over: LITTLE SPRING CREEK

3 MI. SW. OF COLETA, Whiteside, IL

Built 1996 Load: 32.4 t ADT: 25

LAKE ROAD (TR 31)

Fair

Over: BRANCH ROCK CREEK

5 MI. N. MORRISON, Whiteside, IL

Built 1994 Load: 32.4 t ADT: 75

CROSBY ROAD

Fair

Over: TRIB. ROCK CREEK

.18 MI N OF RICK RD, Whiteside, IL

Built 2003 Load: 32.4 t ADT: 25

CROSBY RD

Fair

Over: TRIB ROCK CREEK

5 MI N. OF MORRISON, Whiteside, IL

Built 2009 Load: 32.4 t ADT: 25

HILL RD

Fair

Over: ROCK CREEK

3 MI NE ERIE, Whiteside, IL

Built 1982 Load: 32.4 t ADT: 25

ROCK ROAD

Fair

Over: BR OF ROCK CREEK

5 M SW OF MORRISON, Whiteside, IL

Built 1985 Load: 32.4 t ADT: 50

WILMOT ROAD

Fair

Over: LYNN CREEK

5 MI SW OF MORRISON, Whiteside, IL

Built 1987 Load: 32.4 t ADT: 50

SAND RD.

Fair

Over: CATTAIL CREEK

2 MI SE OF FULTON, Whiteside, IL

Built 1988 Load: 32.4 t ADT: 25

ACKER RD

Fair

Over: BNSF RR

3 MI E OF FULTON, Whiteside, IL

Built 1997 Load: 32.4 t ADT: 150

PALMER RD

Fair

Over: CEDAR CREEK

.56 MI W ELSTON RD, Whiteside, IL

Built 2008 Load: 32.4 t ADT: 75

CAPP ROAD

Fair

Over: SPRING CREEK

6 MI NW STERLING, Whiteside, IL

Built 1979 Load: 32.4 t ADT: 25

QUINN RD

Fair

Over: SPRING CREEK

5 MI NW OF STERLING, Whiteside, IL

Built 1980 Load: 32.4 t ADT: 50

YORKTOWN ROAD

Fair

Over: BRANCH OF ROCK CREEK

6 MI NE OF MORRISON, Whiteside, IL

Built 1983 Load: 32.4 t ADT: 50

BLUE GOOSE RD

Fair

Over: BRANCH OF ROCK CREEK

7 MI NE OF MORRISON, Whiteside, IL

Built 1986 Load: 32.4 t ADT: 50

MANTON ROAD

Fair

Over: BR LITTLE SPRING CRK

9 MI. NE. MORRISON, Whiteside, IL

Built 1998 Load: 32.4 t ADT: 50

CLARK ROAD

Fair

Over: TRIB. ELKHORN CREEK

2.5 MI NE COLETA, Whiteside, IL

Built 2003 Load: 32.4 t ADT: 100

YORKTOWN RD

Fair

Over: ROCK CREEK TRIB

6MI NE OF MORRISON, Whiteside, IL

Built 2012 Load: 32.4 t ADT: 50

COUNTY LINE ROAD

Fair

Over: GREEN RIVER

2.5 MI E DEER GROVE, Whiteside, IL

Built 1978 Load: 32.4 t ADT: 75

FREEPORT ROAD

Fair

Over: GREEN RIVER

0.5 M E DEER GROVE, Whiteside, IL

Built 1982 Load: 32.4 t ADT: 50

POLO ROAD

Fair

Over: SUGAR CREEK

3 MI N OF STERLING, Whiteside, IL

Built 1975 Load: 32.4 t ADT: 450

BUELL ROAD

Fair

Over: SKUNK CREEK

6 MI N OF STERLING, Whiteside, IL

Built 1980 Load: 32.4 t ADT: 75

FREEPORT ROAD

Fair

Over: BUFFALO CREEK

9 MI N. STERLING, Whiteside, IL

Built 1990 Load: 32.4 t ADT: 75

PENROSE RD

Fair

Over: SKUNK CREEK

6 MI. N. OF STERLING, Whiteside, IL

Built 1997 Load: 32.4 t ADT: 125

JAMES ROAD

Fair

Over: BUFFALO CREEK

9 MI N OF STERLING, Whiteside, IL

Built 1998 Load: 32.4 t ADT: 50

BUNKER HILL ROAD

Fair

Over: FEEDER OF ROCK RIVER

4 MI SE OF MORRISON, Whiteside, IL

Built 1989 Load: 32.4 t ADT: 150

TR-105 Crosby Rd

Fair

Over: Rock Creek

.5M NW MORRISON, Whiteside, IL

Built 2001 Load: 32.4 t ADT: 650

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

Related

Browse all → | Rankings →
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.