US Bridges

US 30 over Sunfish Slough

Fair

Whiteside County, Illinois · 0.7 Mi. W. of Il 84 · Structure no. 098010600000000

Built
1999
26 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
440 ft
6 main spans
Daily traffic
9,650
2023 count
Owner
State
State Highway Agency

About this bridge

US 30 over Sunfish Slough is a steel continuous stringer/multi-beam or girder carrying US 30 over Sunfish Slough in Whiteside County, Illinois. It was built in 1999, so it is 26 years old, younger than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 9,650 vehicles a day, roughly 13% of them trucks, projected to reach 11,716 by 2046. The structure is 440 ft (134.1 m) long and 43 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS 30
CrossesSunfish Slough
Location0.7 Mi. W. of Il 84
RouteU.S. Route 30
CountyWhiteside County
StateIllinois
Coordinates41.83801, -90.17109
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating91.8 US tons
Inventory rating55 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length440 ft (134.1 m)
Longest span85 ft (25.9 m)
Deck width43 ft (13 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,650 (2023)
Projected traffic11,716 by 2046
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 30 over Sunfish Slough built?

It was built in 1999, making it 26 years old in 2025.

What condition is US 30 over Sunfish Slough in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in November 2023.

How much traffic does US 30 over Sunfish Slough carry?

About 9,650 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is US 30 over Sunfish Slough?

The structure is 440 ft (134.1 m) long with a longest span of 85 ft (25.9 m) and a deck 43 ft wide.

Who owns US 30 over Sunfish Slough?

It is owned by the State Highway Agency.