Kentucky Route 80 (KY 80) is a state highway in the southern part of the U.S. state of Kentucky. The route originates on the state's western border at Columbus in Hickman County and stretches across the southern portion of the state, terminating southeast of Elkhorn City on the Virginia state line. It is the longest Kentucky State Highway, though the official distance as listed in route logs is much less due to multiple concurrencies with U.S. Route 68 (US 68) and US 23. The route was split into two segments from 2003 to November 2009. Construction and relocation of KY 80 in Graves, Calloway, and Marshall counties during this time caused the route to be split. A new, four-laned section of KY 80 opened in Calloway County on November 25, 2009. The route is now four-lanes from Mayfield to Bowling Green after the widening to four lanes from Canton to Cadiz was completed in 2020. Route description Jackson Purchase region From Columbus, the road passes through Hickman, Carlisle, and Graves counties to Mayfield. Before 2003, the road passed through Mayfield and into Marshall County before converging with US 68 in Aurora. The two-lane segment of former KY 80 from Mayfield to Aurora now has two separate designations. From Mayfield to Brewers in Marshall County, the road retains its former co-designation as KY 58. The segment from Brewers to Aurora is now designated as KY 402. From Mayfield, KY 80 travels along a new four-lane corridor into Calloway County and on to Murray. The route continues through eastern Calloway County and into Marshall County before converging with US 68 near the eastern terminus of KY 402 in Aurora. Lake Barkley and Kentucky Lake to Somerset From Aurora, it follows US 68 through Trigg, Christian, Todd, and Logan counties to Bowling Green (Warren County). From Bowling Green through Glasgow to Edmonton, Kentucky Route 80 remains overlapped with US 68 serving eastern Warren, Barren and Metcalfe Counties until it goes a little past downtown Edmonton. From Glasgow to Somerset, KY 80 is paralleled (and largely supplanted) by the Louie B. Nunn Cumberland Parkway, which is officially designated as the future route of Interstate 66 (I-66), although interest in that project has been lost. KY 80 serves rural portions of Barren, Metcalfe (including the city of Edmonton), Adair, Russell, and Casey counties to Somerset (Pulaski County). Somerset to Hazard Between Somerset and London (Laurel