 Interstate 93's southern terminus is at exit 12 of I-95 in Canton, co-signed with U.S. Route 1 North.At this junction, I-95 North heads to the northwest (co-signed with U.S. Route 1 South, as well as Route 128, which begins at the interchange), to serve as the beltway around Boston, while I-95 South runs by itself southwest through Boston's southwestern suburbs toward Rhode Island.This violates the numbering plan for the highway system of the United States, which dictates that the signed number for odd-numbered interstates increase from west to east, and therefore I-95 should be farther east than I-93.