Structure 38004800000000 · Iroquois County, IL

Ill 54 over I 57

Carries Ill 54 over I 57, Onarga Interchange.

Overall conditionPoor

Set by its lowest-rated component: Deck at 4 of 9.

How ratings work
Decksets the rating4/9 · Poor
Superstructure6/9 · Satisfactory
Substructure5/9 · Fair
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT222 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 4/9 · sets the ratingSuperstructure 6/9Substructure 5/9

222 ft end to end, longest span 67 ft: about 3 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built196759 years old
Length222.1 ft67.7 m
Daily traffic1,150counted 2023
Last inspectedJanuary 2024every 24 months

Location

StateIllinois
CountyIroquois
LocationOnarga Interchange
CarriesIll 54
CrossesI 57
Coordinates40.71478, -88.02845

Physical Characteristics

MaterialSteel Continuous
DesignStringer/Multi-beam
Total Length222.1 ft (67.7 m)
Max Span66.9 ft (20.4 m)
Deck Width57.7 ft (17.6 m)
Deck Area1191.5 sq m
Main Spans4
Year Built1967

Traffic

Avg Daily Traffic1,150 (2023)
Truck Traffic18%
Lanes On Bridge2
Lanes Under Bridge4

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number038004800000000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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