Bridge conditions in McHenry County, Illinois 227 inventoried bridges · 48 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions 2025 National Bridge Inventory, FHWA Compiled August 20, 2026
Of the 227 McHenry County bridges in the federal inventory, 48 carry a poor rating. That 21.1% share is roughly 3x the national average.
48 of the 227 bridges in McHenry County, Illinois, are rated in poor condition (21.1%) in the 2025 National Bridge Inventory, as of August 20, 2026 .92 bridges (40.5%) are rated good and 87 (38.3%) fair.
The median McHenry County bridge was built in 1985 .
The busiest poor-rated bridge is US 12 over Nippersink CR Overfl (built 1939), carrying about 11,500 vehicles a day.
Good 40.5% · Fair 38.3% · Poor 21.1% of 227 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 US 12 over Nippersink CR Overfl 1939 11,500 Poor Bull Valley Road over Boone Creek 1969 9,300 Poor US 12 over N Br Nippersink Crk 1990 8,250 Poor Charles Rd over Slough Creek 1947 6,300 Poor Algonquin Rd over Spring CR 1986 3,200 Poor Dartmoor Drive over Boone Creek 1998 2,550 Poor South St Rd over Franklinville CR 1983 2,050 Poor CH43 (millstream R over Kishwaukee River 1964 1,700 Poor CH-43 Millstream R over S Br Kishwaukee Rvr 1964 1,700 Poor Flat Iron Road over Mokeler Creek 1950 1,550 Poor Bay Road over Unnamed Tributary 1980 1,550 Poor Fas-39 (hunter Roa over Little Beaver Creek 1963 1,350 Poor Barreville Rd over Sleepy Hollow Creek 1957 1,350 Poor Vander Karr Rd over Br of Nippersink CR 1981 1,350 Poor Maple Rd. C.h.(t-5 over Trib Coon Creek 1945 1,150 Poor Oakwood Drive over Boone Creek 1971 1,150 Poor Melody Lane over Silver Creek 1984 1,050 Poor North Union Road over Kishwaukee River 1959 875 Poor Marengo Road over Rush Creek 1956 850 Poor TR-73 (Allendale R over Nippersink CR 1978 850 Poor Thayer Road over Nippersink Creek 1975 800 Poor Perkins Rd over Franklinville CR 1980 725 Poor Harmony Road over Coon Creek 1980 725 Poor Haegers Bend Rd over Fox Riv Inlet 1986 650 Poor MS-1000 QueenAnneR over Nippersink 1960 575 Poor Queen Anne Rd over Br of Nippersink CR 1960 575 Poor MS-3020 Center St over Stream 1991 575 Poor County Line Rd over Piscasaw Creek 1959 475 Poor County Line Rd over Kishwaukee Overflow 1978 475 Poor Lake View Drive over Island Lake 1975 450 Poor Streit Road over Piscasaw Creek 1959 425 Poor Mccue Road over Kishwaukee River 1973 400 Poor Graf Road over Piscasaw Creek 1998 375 Poor Frohling Rd over S Br Kishwaukee 1978 325 Poor Pleasant Valley Rd over Kishwaukee River 1978 325 Poor Pioneer Rd over Nippersink Creek 1982 325 Poor FAU-165 (W Solon R over N Br Nippersink Cr 1983 325 Poor Ch-27 (johnson Rd) over Nippersink CR 1978 300 Poor Thorne Rd over Kishwaukee Riv 1992 275 Poor Paulsen Rd over N Br Kishwaukee Riv 1959 250 Poor Murray Road over Slough Creek 1968 225 Poor North Union Road over Kishwaukee River 1973 200 Poor Sullivan Road over Trib N Br Kiswke Riv 1965 100 Poor Bunker Hill Road over Rush Creek 1962 100 Poor Bunker Hill Road over Drainage Ditch 1970 100 Poor Root Road over Rush Creek 1900 100 Poor Kunde Rd over Kishwaukee River 1985 75 Poor White Oaks Rd over W Branch Piscasaw CR 1947 50 Poor
Busiest bridges in the county Bridge Built Vehicles/day Condition Il 62 over Fox River 1988 43,100 Fair Il 31 over RR - UP 1971 34,400 Fair Algonquin Road over Woods Creek 2004 31,600 Fair Algonquin Road over Crystal Creek 2004 31,600 Fair Algonquin Road over Gravel Pit Creek 2004 31,600 Fair Rakow Rd (ch V-29) over Crystal Creek 1994 30,600 Good Il 31 & 120 over Boone Creek 1990 30,300 Good I-90 WB over Coon Creek 2013 29,350 Good I-90 EB over Coon Creek 2013 29,350 Good Randall Road over Woods Creek 1969 28,800 Good
Source: FHWA National Bridge Inventory , 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
Every bridge in McHenry County →
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 .