The Sumner Tunnel is a road tunnel in Boston, Massachusetts, USA. It carries traffic under Boston Harbor in one direction, from Logan International Airport and Route 1A in East Boston. The tunnel originally deposited traffic at the west side of the North End but with the completion of the Big Dig, it was modified to have two exits. One travels under I-93 and emerges on the west side of I-93 near Haymarket Subway Station. The other exit routes traffic to I-93 North and Storrow Drive.