US Bridges

US 30 over I-88

Fair

Whiteside County, Illinois · 3 MI East Rock Falls · Structure no. 098009100000000

Built
1972
53 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
319 ft
2 main spans
Daily traffic
4,000
2023 count
Owner
State
State Highway Agency

About this bridge

US 30 over I-88 is a steel continuous stringer/multi-beam or girder carrying US 30 over I-88 in Whiteside County, Illinois. It was built in 1972, so it is 53 years old, older 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 5 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 4,000 vehicles a day, roughly 17% of them trucks, projected to reach 4,343 by 2046. The structure is 319 ft (97.2 m) long and 68 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesUS 30
CrossesI-88
Location3 MI East Rock Falls
RouteU.S. Route 30
CountyWhiteside County
StateIllinois
Coordinates41.75808, -89.63742
Functional classRural Minor 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating87.2 US tons
Inventory rating52.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length319 ft (97.2 m)
Longest span119 ft (36.3 m)
Deck width68 ft (20.7 m)
Roadway width47 ft (14.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,000 (2023)
Projected traffic4,343 by 2046
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 30 over I-88 built?

It was built in 1972, making it 53 years old in 2025.

What condition is US 30 over I-88 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 September 2023.

How much traffic does US 30 over I-88 carry?

About 4,000 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is US 30 over I-88?

The structure is 319 ft (97.2 m) long with a longest span of 119 ft (36.3 m) and a deck 68 ft wide.

Who owns US 30 over I-88?

It is owned by the State Highway Agency.