Question: In what year did the Highway that connects the major metropolitan areas of St. Louis, Louisville and Lexington in Kentucky, Charleston, West Virginia, and Richmond, Virginia open?

full_context: Document 1: Interstate 64 in Kentucky: In the U.S. state of Kentucky, Interstate 64 travels for 191 mi passing by the major towns and cities of Louisville, Frankfort, Lexington and Ashland. It has several major junctions within the state: Interstate 65, Interstate 71, Interstate 264 and Interstate 265 in Louisville, and Interstate 75 in Lexington.
Document 2: Owensboro, Kentucky: Owensboro is a home rule-class city in and the county seat of Daviess County, Kentucky, United States. It is the fourth-largest city in the state by population. Owensboro is located on U.S. Route 60 about 107 mi southwest of Louisville, and is the principal city of the Owensboro metropolitan area. The 2015 population was 59,042. The metropolitan population was estimated at 116,506.
Document 3: Interstate 80 in Wyoming: Interstate 80 (I-80) is a part of the Interstate Highway System that runs from San Francisco to Teaneck, New Jersey. In Wyoming, the Interstate Highway runs 402.780 mi from the Utah state line near Evanston east to the Nebraska state line in Pine Bluffs. I-80 connects Cheyenne, Wyoming's capital and largest city, with several smaller cities along the southern tier of Wyoming, including Evanston, Green River, Rock Springs, Rawlins, and Laramie. The highway also connects those cities with Salt Lake City to the west and Omaha to the east. In Cheyenne, I-80 intersects I-25 and has Wyoming's only auxiliary Interstate, I-180. The Interstate runs concurrently with U.S. Route 30 (US 30) for most of their courses in Wyoming. I-80 also has shorter concurrencies with US 189 near Evanston, US 191 near Rock Springs, and US 287 and Wyoming Highway 789 (WYO 789) near Rawlins. The Interstate has business loops through all six cities along its course as well as a loop serving Fort Bridger and Lyman east of Evanston.
Document 4: Kentucky Route 67: Kentucky Route 67 (KY 67) is a Kentucky State Highway originating at a junction with Interstate 64 near Grayson, Kentucky in Carter County. The route continues through rural ridgetops in Greenup County and briefly touches Boyd County before terminating at U.S. Highway 23 in Greenup County in between Wurtland and Greenup. KY 67 is also known as the Industrial Parkway.
Document 5: Grayson, Kentucky: Grayson is a home rule-class city in and the county seat of Carter County, Kentucky, United States, in the state's northeastern region. The population was 4,217 at the 2010 census. Along with Carter County, the city is closely associated with the nearby Huntington-Ashland, WV-KY-OH Metropolitan Statistical Area being just 9 miles west of the M.S.A's western boundary. The city has grown in size substantially since the opening of Interstate 64 in 1975 through Carter County. Immediately afterwards, Grayson experienced several years of commercial sector growth to serve the Interstate 64 traffic. Since 1990, the city has also seen significant growth in the residential sector with the Interstate making for a faster trip to and from Ashland. Beginning in 1995, AA Highway terminates in Grayson making the city a gateway to the Huntington-Ashland urban area.
Document 6: Hampton Roads Beltway: The Hampton Roads Beltway is a loop of Interstate 64 and Interstate 664, which links the communities of the Virginia Peninsula and South Hampton Roads which surround the body of water known as Hampton Roads and comprise much of the region of the same name in the southeastern portion of Virginia in the United States. It crosses the harbor of Hampton Roads at two locations on large four-laned bridge-tunnel facilities: the eastern half carries Interstate 64 (and U.S. Route 60) and uses the Hampton Roads Bridge-Tunnel and the western half carries Interstate 664 and uses the Monitor-Merrimac Memorial Bridge-Tunnel. The beltway has the clockwise direction (as looking down at a map of the area) signed as the Inner Loop, and the counter-clockwise direction signed as the Outer Loop. The entire beltway, including the bridge-tunnels, is owned and operated by the Virginia Department of Transportation.
Document 7: U.S. Route 460: U.S. Route 460 is a spur of U.S. Route 60. It currently runs for 655 miles (1,054 km) 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 to Frankfort, Kentucky, the state capital. It goes through the cities of Norfolk, Portsmouth, Suffolk, Petersburg, Farmville, Lynchburg, Roanoke, Blacksburg, Tazewell, and Grundy, in Virginia; Princeton and Bluefield in West Virginia; and Pikeville, and Frankfort, Kentucky.
Document 8: Interstate 40: Interstate 40 (I-40) is a major east-west Interstate Highway running through the south-central portion of the United States generally north of Interstate 10 and Interstate 20 but south of Interstate 70. The western end is at Interstate 15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 and North Carolina Highway 132 in Wilmington, North Carolina. It is the third longest interstate in the United States, behind Interstate 80 and Interstate 90. Much of the western part of I-40, from Oklahoma City to Barstow, parallels or overlays the historic U.S. Route 66, east of Oklahoma City the route generally parallels U.S. Route 64 and U.S. Route 70. I-40 runs through many major cities including Albuquerque, New Mexico; Amarillo, Texas; Oklahoma City, Oklahoma; Little Rock, Arkansas; Memphis, Tennessee; Nashville, Tennessee; Knoxville, Tennessee; and Raleigh, North Carolina.
Document 9: Interstate 71: Interstate 71 (I-71) is a north-south (physically northeast-southwest) Interstate Highway in the Great Lakes/Midwestern and Southeastern region of the United States. Its southern terminus is at an interchange with Interstate 64 and Interstate 65 (the Kennedy Interchange) in Louisville, Kentucky. Its northern terminus is at an interchange with Interstate 90 in Cleveland, Ohio. I-71 runs concurrently with Interstate 75 from a point about 20 mi south of Cincinnati, Ohio into downtown Cincinnati. Almost three quarters of the route lies east of I-75, thereby putting it out of its proper place in the Interstate grid.
Document 10: Interstate 85 in Virginia: Interstate 85 (I-85) is a part of the Interstate Highway System that runs from Montgomery, Alabama to Petersburg, Virginia. In Virginia, the Interstate Highway runs 68.64 mi from the North Carolina state line near Bracey north to I-95 in Petersburg. I-85 passes through the eastern part of Southside Virginia, where it parallels U.S. Route 1 (US 1) from Petersburg, where the highway runs concurrently with US 460, to south of South Hill, where the highway intersects Southside's major east–west highway, US 58. The Interstate Highway is the primary connection between the Richmond–Petersburg metropolitan area and the Research Triangle and other major metropolitan areas of North Carolina. Like all mainline Interstate Highways, I-85 is a part of the National Highway System for its entire length in Virginia.
Document 11: Griffytown, Louisville: Griffytown is a neighborhood of Louisville, Kentucky located in unincorporated Jefferson County, along Old Harrods Creek Road. Streets within its boundaries include: Bellewood Road, Robert Road, Church Lane, Lincoln Way, Cox Lane, Malcolm Avenue, Plainview Avenue and Booker Road. In 1879, a freed slave named Dan Griffith, an African American, purchased the land he had been living on in the area and the neighborhood appears to be named for him. The neighborhood was redeveloped in the 1970s through urban renewal and remains predominantly African American, although a number of families of other races live there as well.
Document 12: Springfield Interchange: The Springfield Interchange, also known as the Mixing Bowl, is the interchange of Interstate 95, Interstate 395, and Interstate 495 in Springfield, Virginia, outside of Washington, D.C. The interchange is located at exit 57 on the Capital Beltway, exit 170 on I-95, and exit 1 on I-395.
Document 13: Gray, Kentucky: Gray is an unincorporated community in Knox County, Kentucky, United States. The community is located along U.S. Route 25E 4.9 mi west of Corbin. Gray has a post office with ZIP code 40734, which opened on January 25, 1888.
Document 14: Morehead, Kentucky: Morehead is a home rule-class city located along US 60 (the historic Midland Trail) and Interstate 64 in Rowan County, Kentucky, in the United States. It is the seat of its county. The population was 6,845 at the time of the 2010 U.S. census.
Document 15: Interstate 64: Interstate 64 (I-64) is an Interstate Highway in the Eastern United States. Its western terminus is at I-70, U.S. Route 40 (US 40), and US 61 in Wentzville, Missouri. Its eastern terminus is at an interchange with I-264 and I-664 at Bowers Hill in Chesapeake, Virginia. I-64 connects the major metropolitan areas of St. Louis, Louisville and Lexington in Kentucky, Charleston, West Virginia, and Richmond, Virginia.
ground_truth: 1975