The Central Artery, officially the John F. Fitzgerald Expressway, is a section of freeway in downtown Boston, Massachusetts, designated as Interstate 93, U.S. Route 1 and Route 3. It began its life in the 1950s as a partly-elevated and partly-tunneled divided highway, but is now mostly made up of tunnels that were built during a ten-year period from the mid 1990s to the early 2000s as part of the Big Dig (Central Artery/Tunnel) project. The former route of the above ground Artery, known locally as "the other Green Monster" was replaced mostly by open space known formally as the Rose Kennedy Greenway.
According to MassGIS data, the Fitzgerald Expressway runs from the Massachusetts Avenue Connector in South Boston to the split with U.S. Route 1 in Charlestown.
