Details on Green Line retaining walls and noise barriers Post published:May 30, 2012 Post category:Green Line MassDOT has posted its presentation on retaining walls and noise barriers, from the May 22 public hearing. You Might Also Like Join the Green Line construction working group November 18, 2017 WGBH: MBTA Board would like third party to review Green Line estimates September 1, 2015 Updated maps of Green Line options November 13, 2004