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?

Context paragraphs:
U.S. Route 250 in Virginia: U.S. Route 250 (US 250) is a part of the U.S. Highway System that runs from Sandusky, Ohio to Richmond, Virginia.  In Virginia, the U.S. Highway runs 166.74 mi from the West Virginia state line near Hightown east to its eastern terminus at US 360 in Richmond.  US 250 is the main east–west highway of Highland County, which is known as Virginia's Little Switzerland; the highway follows the path of the 19th century Staunton and Parkersburg Turnpike.  From Staunton east to Richmond, the U.S. Highway serves as the local complement to Interstate 64 (I-64), roughly following the 18th century Three Notch'd Road through Waynesboro and Charlottesville on its way through the Shenandoah Valley, its crossing of the Blue Ridge Mountains at Rockfish Gap, and the Piedmont.  In the Richmond metropolitan area, US 250 is known as Broad Street, a major thoroughfare through the city's West End and downtown areas.

Tudor's Biscuit World: Tudor's Biscuit World is a restaurant chain based in Huntington, West Virginia, most commonly found in West Virginia.  Many West Virginia locations share a building with Gino's Pizza and Spaghetti, although the chain is more extensive than Gino's (which is exclusive to West Virginia), having locations in southern Ohio, eastern Kentucky, and southwestern Virginia.  In 2016 a franchise was opened in Panama City, Florida.  Tudor's serves biscuits, biscuit sandwiches, homestyle breakfasts and dinners, muffins, and several side dishes.  The chain was originally based in Charleston, West Virginia and many of the biscuit sandwiches are named for sports teams of interest in that area, including teams at Marshall University, West Virginia University, and The University of Charleston.

Charleston, West Virginia metropolitan area: The Charleston Metropolitan Statistical Area, as defined by the United States Census Bureau, is an area consisting of three counties in West Virginia, anchored by the city of Charleston.  It is the largest metropolitan area entirely within the state of West Virginia.  While the Huntington Metro Area is more populous, it spans three states (West Virginia, Kentucky, and Ohio), and the core county of the Charleston area, Kanawha County, is more populous than the West Virginia portion of the Huntington area.

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.

Interstate 79: Interstate 79 (abbreviated I-79) is an Interstate Highway in the eastern United States, designated from Interstate 77 in Charleston, West Virginia to Pennsylvania Route 5 and Pennsylvania Route 290 in Erie, Pennsylvania.  It is a primary thoroughfare through western Pennsylvania and West Virginia, and makes up part of an important corridor to Buffalo, New York, and the border with Canada.  Major metropolitan areas connected by I-79 include Charleston and Morgantown in West Virginia, and Pittsburgh, and Erie in Pennsylvania.

Home Ride: Home Ride is a private bus service connecting James Madison University, Radford University, University of Virginia, and Virginia Tech to the metropolitan areas of Northern Virginia, Hampton Roads, and Richmond.  Home Ride runs outbound service from the universities on Friday afternoons and return service Sunday afternoons, allowing students from Virginia's major metropolitan areas to return home for a weekend without needing a car on campus; it also runs similar service around the schools' holiday breaks.

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.

U.S. Route 33 in Virginia: U.S. Route 33 (US 33) is a part of the U.S. Highway System that runs from Elkhart, Indiana to Richmond, Virginia.  In Virginia, the U.S. Highway runs 135.60 mi from the West Virginia state line near Rawley Springs east to its eastern terminus at SR 33 in Richmond.  US 33 is the primary east–west highway of Rockingham County, which lies in the Shenandoah Valley.  The highway connects the independent city of Harrisonburg (which also serves as the seat of Rockingham County), the town of Elkton, and an entrance to Shenandoah National Park.  East of the Blue Ridge Mountains, US 33 connects the Piedmont communities of Stanardsville, Gordonsville, and Louisa.  The U.S. Highway is a major suburban and urban route in the Richmond metropolitan area.  Within Richmond, US 33 runs concurrently with US 250.  SR 33 continues from US 33's eastern terminus as a state-numbered extension of the U.S. Highway that connects Richmond with Virginia's Middle Peninsula.

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.

Interstate 85: Interstate 85 (I-85) is a major Interstate Highway in the Southeastern United States.  Its current southern terminus is at an interchange with I-65 in Montgomery, Alabama; its northern terminus interchanges with I-95 in Petersburg, Virginia, near Richmond.  It is nominally north–south, but physically mostly northeast–southwest.  While most interstates that end in a "5" are cross-country routes, I-85 is mainly a regional route, serving five southeastern states.  Major metropolitan areas served by I-85 include the Greater Richmond Region in Virginia, the Research Triangle, Piedmont Triad, and Metrolina regions of North Carolina, Upstate South Carolina, the Atlanta metropolitan area in Georgia, and the Montgomery metropolitan area in Alabama

Supporting paragraphs: Grayson, Kentucky Interstate 64
Answer: 1975