Kentucky Route 40 is a state highway

State highway

State highway, state road or state route can refer to one of three related concepts, two of them related to a state or provincial government in a country that is divided into states or provinces :#A...

 in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Kentucky

Kentucky

The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...

. The road begins at a junction with U.S. Route 460

U.S. Route 460

U.S. Route 460 is a spur of U.S. Route 60. It currently runs for 655 miles from Norfolk, Virginia at U.S. Route 60 at Ocean View to Frankfort, Kentucky at U.S. Route 60. It passes through the states of Virginia, West Virginia, and Kentucky...

 in Salyersville

Salyersville, Kentucky

Salyersville is a city in and the county seat of Magoffin County, Kentucky, United States. It is located on the Licking River. The population was 1,604 at the 2000 census.-History:...

 in Magoffin County

Magoffin County, Kentucky

Magoffin County is a county located in the U.S. state of Kentucky which was formed from parts of Floyd, Johnson, and Morgan Counties and officially created on 22 February 1860. As of 2000, the population was 13,332. Its county seat is Salyersville...

, then continues eastward through Paintsville

Paintsville, Kentucky

-Demographics:As of the census of 2000, there were 4,132 people, 1,681 households, and 1,079 families residing in the city. The population density was 786.1 people per square mile . There were 1,901 housing units at an average density of 361.7 per square mile...

 in Johnson County

Johnson County, Kentucky

Johnson County is a county located in the U.S. state of Kentucky. It was formed in 1843. As of 2000, the population was 23,445. Its county seat is Paintsville...

. KY 40 ends in Martin County

Martin County, Kentucky

Martin County is a county located in the U.S. state of Kentucky. As of 2010, the population was 12,929. Its county seat is Inez. The county is named for Congressman John Preston Martin...

at an intersection with KY Route 292 and an access bridge to U.S. 52 at the West Virginia border. The road was featured during the 1980s in a song by Ricky Skaggs "Highway 40 Blues".