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Chain of Rocks Roa over over Il 255 (FAP310)

Madison County, Illinois · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

Chain of Rocks Roa over over Il 255 (FAP310) in Madison County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
It was built in 1994, making it 31 years old at the 2025 inventory.
It carries about 2,200 vehicles a day (traffic count year 2021).
Its listed owner is the state highway agency.
It is one of 231 of the 524 inventoried bridges in Madison County rated fair (44.1%); 46 (8.8%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Continuous steel stringer or multi-beam girder
Length	about 478 ft
Location	2 M West of Il 157
NBI structure number	060024500000000
Condition class	Fair

Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.

Bridge	Built	Vehicles/day	Condition
Fai 270 over Mississippi River	1966	46,200	Fair
I-270 EB & WB over Chain of Rocks Canal	2014	46,200	Good
Fai 270 EB over Mississippi River	2024	46,200	Good
Fai 270 over Water Main	1964	46,200	Good
I-55/70 over Brush Creek	1962	46,000	Fair
Fai 70 over Canteen Ck	1939	45,600	Good