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Bridge conditions in Grundy County, Illinois

268 inventoried bridges · 76 rated poor · 2025 National Bridge Inventory

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

Of the 268 Grundy County bridges in the federal inventory, 76 carry a poor rating. That 28.4% share is roughly 4x the national average.

76 of the 268 bridges in Grundy County, Illinois, are rated in poor condition (28.4%) in the 2025 National Bridge Inventory, as of August 20, 2026.
97 bridges (36.2%) are rated good and 95 (35.4%) fair.
The median Grundy County bridge was built in 1984.
The busiest poor-rated bridge is Ill 47 over Armstrong & B & O RR (built 1978), carrying about 21,000 vehicles a day.

Good 36.2% · Fair 35.4% · Poor 28.4% of 268 bridges

Bridges rated poor

Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.

Bridge	Built	Vehicles/day	Condition
Ill 47 over Armstrong & B & O RR	1978	21,000	Poor
Ill 47 over Buchanan St	1978	21,000	Poor
US 6 over Aux Sable CR	1969	7,050	Poor
US 6 over CSX Railroad	1974	7,050	Poor
Broadway St N/MS60 over Claypool Drain Ditch	1982	1,850	Poor
Ashton Rd / TR 106 over Fai 80	1958	1,650	Poor
TR-204 Dresden Rd over Com.Ed.Flumes	1975	1,400	Poor
Ch-41 over Granary Creek	1977	1,400	Poor
FAS-1273 (DuPont R over Waupecan Creek	1957	1,350	Poor
Ch 15 over E Fk Mazonriver	1977	1,350	Poor
Grand Ridge Road over Hog Run	1939	1,100	Poor
Grand Ridge Road over Bills Run	1939	1,100	Poor
Grand Ridge Road over Waupecon Creek	1939	1,100	Poor
FAS-292 Gardner Rd over Murray Sluice	2002	1,000	Poor
FAS-292 Gardner Ro over W Fork Mazon River	1982	1,000	Poor
Armstrong Street over I&m Canal	1990	1,000	Poor
Gardner Rd/fas 292 over Johnny Run	1992	900	Poor
Calhoun St over Ill Michigan Canal	1930	825	Poor
DuPont Rd/FAS1273 over Hog Run	1975	775	Poor
Tr 172 Jugtown Rd over Claypool Drain Ditch	1986	775	Poor
Ch 27 Lisbon Rd over Saratoga Creek	1985	750	Poor
Braceville Rd Ch C over Creek	1963	750	Poor
Cemetery Rd Tr-25 over Aux Sable CR	1979	750	Poor
Minooka Rd FAU400 over Trib to Aux Sable CR	1984	625	Poor
Johnson St over Nettle CR	1971	600	Poor
Northern Ave over Nettle Creek	1969	525	Poor
Tr-174a Tabler Rd over I & M Canal	1961	450	Poor
TR184 Carbon Hill over Claypool Drain Ditch	1981	400	Poor
Brown Rd / TR 150 over Fai 80	1960	350	Poor
Gore Rd. Tr-41 over W. Fk. Nettle CR	1990	350	Poor
North Rd Tr-11 over Collins Run	1976	350	Poor
Tr-61 Southmor Rd over Waupecan Creek	1980	350	Poor
Tr-110 Dwight Rd over Johnny Run	1981	325	Poor
Tr 115 over Murray Sluice	1996	275	Poor
TR-7 (Airport Road over East Fork Nettle CR	1980	250	Poor
FAS 1273/DuPont Rd over Armstrong Run	2006	250	Poor
Tr 86 Saratoga Rd over W Fork Nettle Creek	1983	250	Poor
Tr 106 Ashton Rd over E Fk Nettle Creek	1986	250	Poor
Tr 77 over Claypool Ditch	2001	250	Poor
Tr-107b Reed Rd over Johnny Run	1940	225	Poor
Nelson Rd Tr-15 over E. Fk. Nettle CR	1991	200	Poor
Kinsman Road over Waupecon Creek	1948	175	Poor
Twp Rd Tr 70 over Fai 80	1958	150	Poor
TR-7 (Aiport Road) over W Fork Nettle Creek	1979	150	Poor
TR-7 (Airport Road over W Fork Nettle Creek	1975	150	Poor
Nettle Creek Rd Ch over West Fork Nettle CR	1976	150	Poor
Tr 78 over W Fork of Nettle Crk	1996	150	Poor
TR120 Oldmazon Rd over Murray Sluice	1981	150	Poor
TR70 Scottschool R over West Fork Nettle CR	1981	125	Poor
Tr 110 Dwight Rd over Waupecon Creek	1985	125	Poor
Tr-113 Braceville over W. Fork Mazon River	1910	125	Poor
TR-14 Nettle Crk R over Trib To Nettle Crk	1977	100	Poor
Tr-91b Valerio Rd over Claypool Dr Ditch	1916	100	Poor
Higgins Rd Tr-130 over Johnny Run	1977	100	Poor
Tr 130 Higgins Rd over Trib to Mazon River	1987	100	Poor
Brown Road Tr-150 over Walley Run	1979	75	Poor
Tr 140 Campbell Ro over Johnny Run Creek	1982	75	Poor
Baker Rd Tr-108 over Waupecon CR	1978	75	Poor
Spring Rd Tr-105 over Johnny Run Creek	1980	75	Poor
Tr-128 Tynan Rd over Murray Sluice	1981	75	Poor
Hadden Rd Tr-102 over Johnny Run Creek	1975	75	Poor
Old Mazon Rd Tr 12 over W Fk Mazon River	1983	75	Poor
Prairie Rd Tr-123a over Murray Run	1976	75	Poor
Tr-84 Ward Rd over Johnny Run	1978	75	Poor
Tr 161 Stonewall R over Trib E Fk Mazon R	1988	75	Poor
Halpin Rd Tr-208 over TR1B E. Fk.mazon Riv	1991	75	Poor
Tr 120 Old Mazon R over Johnny Run Creek	1982	50	Poor
Goodfarm Rd Tr 155 over E Fork Mazon River	1978	50	Poor
Tr 155/GOODFARM Rd over E Fork Mazon River	1999	50	Poor
Tr 155 Goodfarm Rd over Trib E Fk Mazon Riv	1987	50	Poor
Goodfarm Rd Tr-155 over Trib E Fk Mazon Riv	1980	50	Poor
Storm Rd Tr-180 over East Fk Mazon River	1979	50	Poor
Tr-167 Scully Rd over Trib E Fk Mazon Riv	1910	50	Poor
TR159A Stonewall R over Trib E Fk Mazon Riv	1974	50	Poor
Hoge Rd Tr-13 over Trib to Nettle Creek	1976	25	Poor
Tr 2 La Salle Rd over Trib to Johnny Run	1985	25	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
Fai 80 (EB & WB) over Fas285/ch5/ridge Rd	2003	50,300	Fair
Fai 080 (EB & WB) over Walley Run CR	2003	39,100	Good
Fai 80 (EB & WB) over Aux Sable Crk	2003	39,100	Fair
Fai 80 (EB & WB) over Collins Run Creek	2003	39,100	Good
Fai-55 & Or 66 over Woods Run	1979	24,300	Good
I-55 over Brewster Run	1979	22,900	Good
Ill 47 over Armstrong & B & O RR	1978	21,000	Poor
Ill 47 over Buchanan St	1978	21,000	Poor
Il 47 Fap 326 over Il Riv.& I & M Canal	2003	18,100	Fair
Ill 47 over I-80	1997	16,800	Fair

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

Every bridge in Grundy County → - all 268, busiest first, each with its own condition record.

All of Illinois: Illinois bridge conditions by county · every download on the data page.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.