Structure 1002400000000 · Adams County, IL

Ill 104 WB over Mill Creek

Carries Ill 104 WB over Mill Creek, 2.2mi E I-172/IL 104.

Overall conditionFair

Set by its lowest-rated component: Deck and Superstructure and Substructure at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructuresets the rating6/9 · Satisfactory
Substructuresets the rating6/9 · Satisfactory
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT168 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 6/9

168 ft end to end: about 2 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.

Built1928rebuilt 1975
Length168.0 ft51.2 m
Daily traffic6,150counted 2023
Last inspectedDecember 2024every 24 months

Location

StateIllinois
CountyAdams
Location2.2mi E I-172/IL 104
CarriesIll 104 WB
CrossesMill Creek
Coordinates39.93059, -91.28299

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length168.0 ft (51.2 m)
Max Span101.4 ft (30.9 m)
Deck Width40.7 ft (12.4 m)
Deck Area634.9 sq m
Main Spans1
Year Built1928 (reconstructed 1975)

Traffic

Avg Daily Traffic6,150 (2023)
Truck Traffic7%
Lanes On Bridge2

Inspection & Ownership

Last InspectionDecember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure Number001002400000000

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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