Question: What is the population of the town at the intersection of Interstate Highways 77 and  the longest Interstate highway within the borders of Virginia?

 In the U.S. state of Virginia, I-81 runs for 324.92 mi , making the portion in Virginia longer than any other state's portion.  It is also the longest Interstate highway within the borders of Virginia. Interstate 81 (I-81) is an 855 mi highway.  It stretches from the Tennessee state line near Bristol to the West Virginia state line near Winchester. <SEP> Wytheville ( ) is a town in, and the county seat of, Wythe County, Virginia, United States.  Wytheville's population was 8,211 at the 2010 census.  It is named after George Wythe, a signer of the United States Declaration of Independence, and mentor to Thomas Jefferson.  Located at the intersection of Interstate Highways 77 and 81, the town has long been a crossroads for travelers.  During the American Civil War, Wytheville had a strategic importance, and was attacked in 1863 (Toland's Raid) and 1865 (Stoneman's 1865 Raid).  The town is also the birthplace of Edith Bolling Wilson, wife of President Woodrow Wilson. <SEP> The following is a list of Interstate Highways in Maryland.  There are currently 16 Interstate Highways that exist entirely or partially in the U.S. state of Maryland.  Six of these are primary Interstates while ten are auxiliary Interstates related to one of the primary Interstates.  The longest primary Interstate in Maryland is Interstate 95 (commonly abbreviated I-95) at 110.01 mi .  The shortest primary Interstate in Maryland is I-81 at 12.08 mi .  I-97 is the shortest primary Interstate at 17.62 mi and the shortest intrastate Interstate.  I-97 is also the only primary Interstate to be located entirely within one county and to not connect with any other primary Interstate.  The longest auxiliary Interstate in Maryland is I-695 at 51.48 mi .  The shortest auxiliary Interstate in Maryland is I-295 at 0.80 mi .  All Interstates are maintained by the Maryland State Highway Administration except for all of I-395, all of I-895, a small part of I-695, I-95 within and north of Baltimore, and I-83 within Baltimore.  Maryland has one unsigned Interstate, I-595; that highway is marked as U.S. Route 50 and US 301, which are concurrent with I-595 for its entire length.  Maryland has one former Interstate, I-170, which is shaded in dark gray in the list. <SEP> 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.