Kentucky supplemental roads and rural secondary highways are the lesser two of the four functional classes of highways constructed and maintained by the Kentucky Transportation Cabinet, the state-level agency that constructs and maintains highways in Kentucky. The agency splits its inventory of state highway mileage into four categories:[1]
The State Primary System includes Interstate Highways, Parkways, and other long-distance highways of statewide importance that connect the state's major cities, including much of the courses of Kentucky's U.S. Highways.
The State Secondary System includes highways of regional importance that connect the state's smaller urban centers, including those county seats not served by the state primary system.
The Rural Secondary System includes highways of local importance, such as farm-to-market roads and urban collectors.
Supplemental Roads are the set of highways not in the first three systems, including frontage roads, bypassed portions of other state highways, and rural roads that only serve their immediate area.
The same-numbered highway can comprise sections of road under different categories. This list contains descriptions of Supplemental Roads and highways in the Rural Secondary System numbered 600 to 699 that do not have portions within the State Primary and State Secondary systems.
Kentucky Route 602 is a 0.690-mile-long (1.110 km) supplemental road in Central City in central Muhlenberg County. The highway begins at KY 277 (River Road) in the north of downtown. KY 602 heads north along an unnamed street and meets the western end of KY 3038 (Prison Road) before reaching its north end at KY 1031 (Second Street).[1][3][4]
Kentucky Route 603 is a 1.701-mile-long (2.737 km) supplemental road in Owensboro in central Daviess County. The highway begins just south of a diamond interchange with the Wendell Ford Expressway, which carries US 60 and US 231 around the south side of Owensboro; the road continues south as Pleasant Valley Road No. 1. KY 603 passes through an S-curve and expands to a four-lane divided highway. The highway crosses over a CSX rail line and reaches its northern terminus at Fourth Street; this intersection also serves as the western terminus of KY 144.[1][5][6] The highway was designated on September 12, 2011.
The original KY 603 ran from US 421 to KY 602 in Central City. This was given to the city on May 5, 1994.
Kentucky Route 604 is a 0.975-mile-long (1.569 km) supplemental road in Central City in central Muhlenberg County. The highway begins at US 431 (Second Street) just south of the U.S. Highway's four–loop ramp interchange with the Western Kentucky Parkway on the eastern edge of the city. KY 604 heads east and then turns north at Youngstown Road. The highway crosses over the parkway before reaching its north end at an acute intersection with US 62 (Everly Brothers Boulevard).[1][3][4]
Kentucky Route 607 is a 17.421-mile-long (28.036 km) rural secondary highway in southern Owen County. The highway begins at US 127 south of Monterey. KY 607 heads east along New Columbus Road, which immediately crosses Cedar Creek and has a hairpin at New. The route intersects KY 227 (Georgetown Road) west of Fairbanks, east of which the highway crosses Caney Creek. KY 607 meets the southern end of KY 1883 (Slatin Road) and meets the eastern end of KY 2018 (Swope Natlee Road) at Natlee, where the route crosses Eagle Creek. The highway continues through New Columbus to its eastern terminus at KY 330 (Owenton Road) at the Owen–Grant county line.[1][7][8]
Kentucky Route 608 is a 4.067-mile-long (6.545 km) state highway that runs from Frogtown Road at the Owen-Scott county line southeast of Natlee to U.S. Route 25 south of Stonewall.
Kentucky Route 614 was a state Highway in Calloway County. It ran from KY 280 east of Pottertown east via Poplar Springs Road. The road was given to Calloway County on June 16, 1985.
Kentucky Route 623 is a 6.087-mile-long (9.796 km) rural secondary highway in southwestern Spencer County. The highway begins at KY 48 (Highgrove Road) just north of the East Fork of Cox Creek, which forms the Spencer–Nelson county line. KY 623 heads north as Lilly Pike, which crosses the Salt River on its way to its north end at KY 44 (Mount Washington Road) east of Waterford.[1][10][11]
Kentucky Route 625 is a 5.064-mile-long (8.150 km) state highway in western Trimble County that runs to and from U.S. Route 421 via Mount Pleasant and Trout.Between Corn Creek Road and US-421 this route is closed to Trucks due to the tight switchbacks and narrow nature of the road.
Kentucky Route 626 is a 17.954-mile-long (28.894 km) rural secondary highway in southeastern Butler County and western Warren County. The L-shaped highway begins at a three-legged intersection with KY 1153, which heads west as Berry's Lick Road and north as Sandy Creek Road. KY 626 heads east along Berry's Lick Road through Turnertown, also known as Berry's Lick. The highway crosses Flat Rock Branch of Muddy Creek and intersects KY 79 (Russellville Road) at Davis Crossroads. KY 626 crosses Neils Creek west of Sharer, where the route has a brief concurrency with KY 1083 (Sugar Grove Road). The highway crosses the Butler–Warren county line and continues east on Jackson Bridge Road. KY 626 crosses the Gasper River and turns north at its junction with KY 2632 (Hammet Hill Road). The highway joins US 231 (Morgantown Road) to cross back over the Gasper River and turns north onto Highland Church Road at Hadley. KY 626 crosses William H. Natcher Parkway; on either side of the parkway, the route meets the eastern ends of a pair of frontage roads, KY 6140 (Frontage Road) and KY 6139 (Clifty Creek Frontage Road) on the north. The highway reaches its eastern terminus at KY 1435 (Barren River Road) at Rockland.[1][15][16][17][18]
Kentucky Route 628 is a 5.225-mile-long (8.409 km) state highway in southwestern Whitley County that runs from a dead end along Wolf Creek northeast of Ayres to U.S. Route 25W and Stringtown Road in Pleasant View.
Kentucky Route 631 is a 15.081-mile-long (24.271 km) rural secondary state highway in Grayson County that runs to and from Kentucky Route 54 east and southeast of Short Creek via Duff.
Kentucky Route 633 is a 1.689-mile-long (2.718 km) supplemental state highway in far northwestern Adair County that runs from Cane Valley Road at the Taylor County line to Kentucky Route 55 and Cane Valley Church Road south of Coburg.
Kentucky Route 636 is a 9.033-mile-long (14.537 km) rural secondary highway in northeastern Spencer County and southeastern Shelby County. The highway begins at KY 248 (Briar Ridge Road) east of Taylorsville Lake. KY 636 heads north along Van Buren Road, which crosses Little Beech Creek on its way to Mount Eden, which sits on the Spencer–Shelby county line. The highway meets the eastern end of KY 1795 (Mill Road) on the Spencer County side and intersects KY 44 (Mount Eden Road) on the Shelby County side. KY 636 continues northeast as Back Creek Road, which crosses and briefly parallels another Little Beech Creek. The highway passes through Junte before reaching its northern terminus at KY 395 (Waddy Road) west of Harrisonville.[1][29][10][30][11]
Kentucky Route 637 was a state Highway in Shelby County. It ran from KY 395 in Waddy southeast to KY 1472. The road was given to Shelby County by August 3, 1981, but was restored on April 8, 1987, as KY 2867.
Kentucky Route 640 is a 16.723-mile-long (26.913 km) rural secondary highway in western Metcalfe County. The highway begins at KY 90 (Summer Shade Road) at Summer Shade. KY 640 heads north along Randolph Summer Shade Road. The highway curves west and crossing Falling Timber Creek and meets the eastern end of KY 1330 (Kino Road) very close to the Metcalfe–Barren county line. KY 640 continues northeast to Randolph, where the route turns north at the north terminus of KY 2387 (Randolph Goodluck Road) and meets the west end of KY 861 (Randolph Road). KY 640 follows Wisdom Road north to its intersection with KY 3234 (Old Glasgow Road) just south of the route's underpass of the Cumberland Parkway. The highway continues as Wisdom Knob Lick Road through an intersection with US 68 (Glasgow Road) at Wisdom to its northern terminus at KY 70 (Sulphur Well Knob Lick Road) west of Knob Lick.[1][34][35]
Kentucky Route 642 was a state Highway in Garrard County. It ran from KY 39 southeast of Lancaster southwest via Golberts Creek Road and Goshen Road to US 150 in Stanford. The section south of the Lincoln/Garrard County Line was given to Lincoln County by August 15, 1980; the remainder was given to Garrard County on August 4, 1997.
Kentucky Route 647 was a state Highway in Montgomery County. It ran from US 60 in Mt. Sterling northeast via Old Owingsville Road. The road was given to Montgomery County on September 26, 1997.
Kentucky Route 649 is a 3.630-mile-long (5.842 km) state highway in northern Elliott County that runs from Kentucky Route 504 east of Ault to Mobley Flats Road and Ibex Post Office Road northeast of Ibex via Beartown and Stark.
Kentucky Route 651 is a 2.207-mile-long (3.552 km) supplemental state highway in western Wolfe County that runs from a point along Sandy Ridge Road to Kentucky Route 15 southwest of Campton.
Kentucky Route 653 is a 6.623-mile-long (10.659 km) rural secondary state highway in southwestern Fulton County that runs from Kentucky Route 94 and Cotton Gin Road to Ash Log Road and Davis Road near Sassafras Ridge.
Kentucky Route 654 is a 8.262-mile-long (13.296 km) rural secondary state highway in eastern Crittenden County that runs from Kentucky Route 120 at Tribune to Baker Hollow Road and Weston Road northwest of Mattoon via Mattoon.
Kentucky Route 655 is a 9.214-mile-long (14.828 km) rural secondary highway in western Edmonson County. The C-shaped highway begins at KY 70 (Morgantown Road) northwest of Windyville. KY 655 follows Segal Road west across Gulf Creek and then south through Segal and east through Asphalt. The highway continues northeast to its terminus at KY 70 at Windyville.[1][51][52][53]
Kentucky Route 669 is a 3.078-mile-long (4.954 km) supplemental state highway in eastern Union County that runs from a point along East Market Street near St. Peter's Catholic Church in southeastern Waverly to Locust Lane and Yancy Greenwell Road southeast of Hitesville via Waverly.
Kentucky Route 673 was a state highway in Fleming County. It ran from KY 11 (now Bus. KY 11) in Flemingsburg north to KY 24 (now Mill Creek Road). The road became part of KY 597 by 1976 (when KY 24 was decommissioned).
Kentucky Route 674 is a 4.205-mile-long (6.767 km) rural secondary state highway in northwestern Wayne County that runs from a point along Bugwood Road to Kentucky Route 92 northwest of Parnell.
Kentucky Route 675 was a state highway in Logan County. It ran from KY 103 in Auburn north to KY 1038 in Gasper via Liberty Church Road. The road was given to the county by March 18, 1982.