Interstate 83 (I-83) is an Interstate Highway located in the states of Maryland and Pennsylvania in the Eastern United States. Its southern terminus is at a signalized intersection with Fayette Street in Baltimore, Maryland; its northern terminus is at I-81 near Harrisburg, Pennsylvania. I-83 runs from Downtown Baltimore north to I-695 near the northern suburb of Timonium on the Jones Falls Expressway before forming a concurrency with I-695. After splitting from I-695, the route follows the Baltimore–Harrisburg Expressway north to the border between Maryland and Pennsylvania. Upon crossing the state line, I-83 becomes the Veterans of Foreign Wars of the United States Memorial Highway and continues north through York toward the Harrisburg area. The route runs along the southern and eastern portion of the Capital Beltway that encircles Harrisburg before reaching its northern terminus.

Interstate 81 (I-81) is a north–south Interstate Highway in the eastern part of the United States. Its southern terminus is at I-40 in Dandridge, Tennessee; its northern terminus is on Wellesley Island, New York at the Canadian border, where the Thousand Islands Bridge connects it to Highway 137 and ultimately to Highway 401, the main Ontario freeway connecting Detroit via Toronto to Montreal. The major metropolitan areas along the route of I-81 include the Tri-Cities of Tennessee; Roanoke in Virginia; Harrisburg and the Wyoming Valley in Pennsylvania; and Syracuse in New York.