The full Green Line Extension is open! Post published:December 12, 2022 Post category:Green Line Hundreds rode the first trains, music was played, mayors (current and former) danced, speeches were given, and Somerville became an even better place to live on this fine December day! Keep reading for more photos from Karen Molloy. You Might Also Like Green Line extension plans – as far back as 1923 November 24, 2013 Boston Globe: Green Line and economic development November 23, 2009 Green Line contract approved amid cost concerns May 2, 2012