 U.S. Route 11 ( US 11 ) is a part of the U.S. Highway System that runs from New Orleans , Louisiana to Rouses Point , New York . In Maryland , the federal highway runs 12 @.@ 83 miles ( 20 @.@ 65 km ) from the West Virginia state line at the Potomac River in Williamsport north to the Pennsylvania state line near Maugansville . US 11 is the primary north – south surface highway in central Washington County , connecting Hagerstown with Williamsport to the south and Hagerstown Regional Airport to the north . The federal highway was once a major long @-@ distance highway , but that role has been assumed by Interstate 81 ( I @-@ 81 ) , which parallels US 11 not only in Maryland but for most of its course from Tennessee to Upstate New York . US 11 is maintained by the Maryland State Highway Administration except for the municipally @-@ maintained portions within the corporate limits of Williamsport and Hagerstown . 
