 It was extended through Somerville and Charlestown to the Central Artery, U.S. Route 1, and the planned route of the Inner Belt between 1965 and 1973.Because it was already under construction, the highway was granted an exception to the moratorium on highway expansion inside Route 128 which was announced in 1970.I-93's original southern terminus was in Cambridge (just north of Boston) where it was to meet the Inner Belt (I-695).