While riding to work along 127 South, I was stopped at 3 rail road crossings ... all for the same MBTA Commuter Rail Train going from Rockport to North Station, Boston.
A very nice ride ... http://goo.gl/maps/HGDTJ 42 miles or so (with a stop at the gym along the way). The old fashion way (before RT 128 ... mostly Routes 127, 62, and a bit of 3A in Burlington).