Bridge conditions in Grundy County, Illinois
268 inventoried bridges · 76 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
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 .
- 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.
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.