Based on Single = 120, Double = 180. 5 cars with 1 double is about 660, 6 with 1 double is about 780, and 6 with 2 doubles is about 840. so based on your list.
Train 154: 642 - 5 w/1, 18 seats to spare (97.3%)
Train 104: 619 - 5 w/1, 41 seats to spare (93.8%)
Train 156: 728 - 6 w/1, 52 seats to spare (93.3%)
Train 106: 691 - 6 w/1, 79 seats to spare (88.6%)
Train 117: 587 - 5 w/1, 73 seats to spare (88.9%)
Train 169: 706 - 6 w/1, 74 seats to spare (90.5%)
Train 119: 585 - 5 w/1, 75 seats to spare (88.6%)
Nothing needs a 6 w/2 based on these counts unless you wanted to leave some extra space somewhere. Certainly daily fluctuation may mean people stand at times, or they choose to front-load the train to rush off once they hit Boston and stand rather than walk through to find a seat. There simply aren't enough coaches though to deal with picking up extra trainloads of people when that happens. Every train would need to be running at about 50% in order to accommodate that.
And as for more doubles on the South it's because they simply have more passengers overall, and bigger trains. It makes sense to have more doubles on the South with counts on some trains exceeding 1300. I took a quick glance through the North and no train exceeded 800. That's a pretty big disparity.
sonicdoommario wrote:Did they change the turns for some of the trains too? For example, 821 would be the turn of 824 when reaching Boston. This week, 824 has been turning to 823 while 821's set would come out of Readville (823 would normally come out of Readville). I think this move makes sense since if 824 was more than a few minutes late, it would delay 821 (and 824 could be late on occasion because of being held up at Providence or Attleboro so an Amtrak could pass it).
If they started moving equipment around then they probably did change some turns too.