 US 11 is the descendant of a trail blazed through the Great Appalachian Valley in the 18th century . In the 19th century , this trail was upgraded to a pair of turnpikes , one from Williamsport to Hagerstown and the second from Hagerstown to the Pennsylvania state line . The highway was constructed in its modern form in the early 20th century , with the bridge across the Potomac River constructed in 1909 and the old turnpikes paved as all @-@ weather roads by the nascent Maryland State Roads Commission in the 1910s . These highways and the streets of Hagerstown and Williamsport were designated Maryland 's portion of US 11 in 1926 . The federal highway was improved outside of the towns in the years surrounding 1930 and again around 1950 . Since the completion of I @-@ 81 in two sections in the late 1950s and mid @-@ 1960s removed long @-@ distance traffic from the highway , US 11 has seen its two major relocations : one that removed the highway from downtown Hagerstown and another required by expansion at Hagerstown Regional Airport . 
