I'm curious, how many tracks do people envision a NSRL being? To be operationally feasible were talking at least 3 tracks each direction right? The cross section of 6 tracks is *massive.* Wouldn't it make more sense to just connect NS and SS with a better transit connection?
Can someone explain the operational benefits of NSRL, like how does it work. Do trains from say Franklin line stop at SS, then go to North station then come back? Do all the incoming trains do this or just some? How is this really any better than a rapid transit link between NS and SS? The dwell times at the stations will be massive anyway given the number of people who will still get off at SS and the inefficiency of boarding a commuter rail train. The congestion in the tunnel would be crazy if you tried to send even half the incoming trains in the morning through it, so chances are commuters would have to get off at SS and change to a train continuing onward. So at that point, why not just change to a nice rapid transit link from SS to NS? It would cost far less than NSRL too.