Thanks for the clarification. I was wrong and it is indeed possible to 100% the map. I did not notice the difference in track speed between the top-most and middle track of the mainline.

Hey folks, so I misread what part of Amtrak 171 was the problem. I thought the problem was getting it turned around and into South Station on time (which is in the most difficult 10 minutes of the level), not sending it out to Route 128. That's on me.
I just replayed the level download straight from the Workshop and was able to 100% it. To make it on time, Atrk171 needs to head up on the northern mainline through Back Bay platform 3 to Forest Hills, where it drops down to the middle track (crossing through Forest Hills platform 2) out to Route 128. It arrives at 8:05:30 on the dot, technically 30 seconds late but far from being penalized.

Late to the party, but Wolfie_ is right: there is no way to get Atrk171 out in time. I used the area you described as a wye and despite that it arrives at its final stop two minutes late.

So, Amtrak 171 is a cheeky one. When I tightened the timetable I didn't notice there wasn't enough time for it to go around the reversing loop and make it back on time... because I had been reversing it into the area right to the east of Back Bay. If you use that section as a wye you'll make it on time, but it is tricky (and perhaps slightly unfair) with all the other traffic.

I believe there to be an error in the timetabling with that train. Backed Atrk171 out of Station South A (9) towards the Newmarket (1) Line, the very second it cleared the appropriate junction, manually set them to create a path around the curved track towards Back Bay (4) and instructed the train to reverse direction. Even with a cleared line to whole way to Route 128 (1) and travelling at 160 kmph, it wasn't able to reach it's destination until 8:07, and thus copped penalty for 2 minutes late.

Currently for Route 128 (1):
Atrk171 @ 8:05 to 8:07
P804 @ 8:08 to 8:10

Seems like should be the other way around, then P804 not having wait around so long and provides a bit of time margin for Atrk171.

Hey,

I tried this map and went through half of the timetable; It's super awesome, the timetable is well made and I love the layout.
There is one train however which I had troubles around, it's Atrk171, I don't know if that was intended but this guy had only one locomotive, and returning it at Boston South I didn't realise this until it was in the middle of a line run, so I had to reverse it and make it go via the loop on the Newmarket line. But other than that, I really had fun and find the timetabling very accurate and satisfying to watch coming along. Kudos!