Scour-Critical Bridges in Illinois

Illinois has 88 bridges rated scour-critical by the Federal Highway Administration. These bridges have foundations that are unstable or at risk of undermining during flood events. Scour-critical doesn't mean a bridge is about to collapse — it means extra monitoring and countermeasures are in place — but these structures are priorities for repair or replacement.

How this ranking works

This state list filters to NBI scour ratings 0 through 3, then sorts by average daily traffic. It is intended to show flood-vulnerability exposure, not to label any bridge as currently unsafe.

Bridge	County	Scour Rating	Daily Traffic	Condition
I-294 NB over Salt CR	Cook	3 — Serious	87,550	Fair
I-294 SB over Salt CR	Cook	3 — Serious	87,550	Fair
Il 120 EB over Des Plaines River	Lake	3 — Serious	30,700	Fair
Il 120 WB over Des Plaines River	Lake	3 — Serious	30,700	Fair
Randall Road over Mill Creek	Kane	3 — Serious	29,900	Fair
Fai 255 EB over Mississippi River	Monroe	3 — Serious	25,850	Fair
Fai 255wb over Mississippi River	Monroe	3 — Serious	25,850	Fair
NB Ill 29 over Dickison Run Creek	Peoria	3 — Serious	14,400	Poor
Jefferson ST over Rock Riv& Madison ST	Winnebago	3 — Serious	8,500	Fair
I-88 WB over 3 Mile Branch	Lee	3 — Serious	7,850	Fair
Fau 9187a & Met Li over Miss Riv/rr/mss6000	St. Clair	3 — Serious	6,550	Fair
Ill 150 over Miss Riv/fau 9416	Randolph	3 — Serious	6,250	Poor
15th AVE over Rock River	Winnebago	3 — Serious	5,750	Poor
Fau 6999(voorhees) over E Fork Lick Creek	Vermilion	3 — Serious	5,000	Poor
Il 57 over Mill Creek	Adams	3 — Serious	4,450	Poor
Prairie Hill RD over Rock River	Winnebago	3 — Serious	4,200	Poor
Fap-877 (ill-141) over Wabash River	White	3 — Serious	3,700	Fair
Ill 15 over Nashville Creek W Branch	Washington	3 — Serious	3,450	Fair
Ill 8 over Trib Of Kickapoo CR	Peoria	3 — Serious	2,550	Fair
Fap 685 Ill 9 over Mississippi River	Hancock	3 — Serious	2,500	Poor
Fau 8173 College A over Mauvaise Terre CR	Morgan	3 — Serious	2,150	Poor
Daysville RD over Kyte Creek	Ogle	3 — Serious	2,100	Good
Seventh Avenue over Kyte Creek	Ogle	3 — Serious	1,600	Poor
Il 17/91 over Spoon River	Stark	3 — Serious	1,600	Poor
First Avenue over Kyte Creek	Ogle	3 — Serious	1,550	Poor
Fau-1560 (91st St) over Flag Creek	Cook	3 — Serious	1,200	Fair
E Milledgeville RT over Elkhorn Creek	Carroll	3 — Serious	1,050	Poor
Fas 206-ch 4 over Camp Creek	Mercer	3 — Serious	950	Fair
State Line Road over Piscasaw Creek	McHenry	3 — Serious	850	Fair
Kerfoot Street over Kerfoot Creek	Tazewell	3 — Serious	775	Fair
Chatham ST over Cal Slough	Cook	3 — Serious	750	Poor
Harmony Road over Coon Creek	McHenry	3 — Serious	725	Poor
Edson Road over Beaver CR	Boone	3 — Serious	700	Poor
Hoover Rd. over Sugar Creek	Whiteside	3 — Serious	675	Fair
Fulfs RD over Elkhorn Creek	Whiteside	3 — Serious	600	Fair
Fas 644 over Sangamon River	Christian	3 — Serious	550	Fair
Fas-721 (ch-1) over Hurricane Creek	Fayette	3 — Serious	550	Fair
Co HWY 14 Fas 1354 over Creek	Livingston	3 — Serious	550	Fair
St. F Muni 7250 over Wabash River	Lawrence	3 — Serious	500	Poor
Tr 257 over Wabash River	Lawrence	3 — Serious	500	Poor
Church ST over Rock Creek	McLean	3 — Serious	500	Good
Science Ridge Road over Spring Creek	Whiteside	3 — Serious	500	Poor
Tr-362 Statelinerd over Clear Creek	Clark	3 — Serious	450	Good
Tr 330 over Sugar Creek	Edgar	3 — Serious	400	Good
Correct Craft LN over Jordan Creek Trib	Will	3 — Serious	350	Good
Olive Street 2455a over Town Creek	Marion	3 — Serious	275	Fair
Fas-1697 (ch-8) over Honey Creek	Crawford	3 — Serious	250	Fair
Tr 136 over Camp Creek	Piatt	3 — Serious	250	Fair
Ch 5 over Panther CR	Woodford	3 — Serious	250	Fair
Oak Knoll Road over Flint Creek	Lake	3 — Serious	225	Fair
Co RD 57 over Vermilion River	LaSalle	3 — Serious	200	Poor
Park Road Tr 515a over I255 & Harding Ditch	St. Clair	3 — Serious	200	Fair
Penrose Road over Elk Horn Creek	Whiteside	3 — Serious	175	Fair
Eagle Road over Tyler Creek	Kane	3 — Serious	150	Poor
Grange RD over Coon Creek	McHenry	3 — Serious	150	Fair
Tr 80 over S Branch Salt Creek	Piatt	3 — Serious	150	Fair
Mill RD over Piscasaw Creek	Boone	3 — Serious	125	Poor
So Second Street over Kyte Creek	Ogle	3 — Serious	125	Poor
Tr-91b Valerio RD over Claypool DR Ditch	Grundy	2 — Critical	100	Poor
Lock & Park Traffi over Henderson River	Henderson	3 — Serious	100	Poor
Tr 24 over Mole Creek	Livingston	3 — Serious	100	Poor
Ch 5 over Clear CR	Putnam	2 — Critical	100	Fair
Bunker Hill RD over Rock Creek	Whiteside	3 — Serious	100	Fair
Fau 6166 over Eagle Creek	LaSalle	3 — Serious	75	Poor
Tr4 over Sugar Creek	McLean	3 — Serious	75	Good
Tr 164 over Sangamon River	Piatt	3 — Serious	75	Fair
Buell Road over Skunk Creek	Whiteside	3 — Serious	75	Fair
Tr-167 Scully RD over Trib E Fk Mazon Riv	Grundy	3 — Serious	50	Poor
Tr 47 over West Fork Mazon R	Livingston	3 — Serious	50	Poor
Tr 150 over Drainage Ditch	Livingston	3 — Serious	50	Poor
Anthony RD over Coon Creek	McHenry	3 — Serious	50	Fair
Fas 1405-ch 12 over Pope Creek	Mercer	3 — Serious	50	Poor
Fas 1210-ch 10 over Edwards River	Mercer	3 — Serious	50	Fair
Tr 91 over Camp Creek	Piatt	3 — Serious	50	Fair
Clark RD over Little Rock Creek	Whiteside	3 — Serious	50	Fair
Capp Road over Elk Horn Creek	Whiteside	3 — Serious	50	Fair
James Road over Buffalo Creek	Whiteside	3 — Serious	50	Fair
Tr 144 over North Fork	Brown	3 — Serious	25	Poor
Tr 2e over Kult Ditch	Iroquois	3 — Serious	25	Good
Tr-2e over Kult Ditch	Iroquois	3 — Serious	25	Good
Tr 29 over Trib E Fork Mazon R	Livingston	3 — Serious	25	Poor
Tr 46 (th-s18) over Br Crow Creek	Marshall	2 — Critical	25	Poor
Fas 1216-ch 3 over Pope Creek	Mercer	3 — Serious	25	Fair
Burton Road over Elkhorn Creek	Whiteside	3 — Serious	25	Fair
Tr 620 A over Stream	Wayne	3 — Serious	10	Poor
Sawyer Road over Little Rock Creek	Whiteside	3 — Serious	10	Fair
Mellotts Road over Trib Of Rock River	Whiteside	3 — Serious	10	Fair
Priv Entr Off Ill1 over Cany Creek	Union	3 — Serious	0	Fair