Re: Fall River/New Bedford Commuter Rail
Would it be cheaper and more feasible reconfigure the red line tracks north of JFK-UMass so that both branches serve the same platform and both branches serve Savin Hill? This way you still free up surface space for an additional CR track and shoulder or managed lane without the tunnel. Would also require track reconfiguration downstream as well to create a new branch split.
No, that would be a terrible idea for exactly the reasons outlined above. It is hideously expensive to build a ventilated RR tunnel with 20+ feet of vertical clearance. It's twice the concrete of a much more compact subway tunnel. There is no upside in HOV's anywhere close to large enough to float the magnitude of that cost.
Bury Red under Red, double-track the CR on the surface, and there is one totally freed track berth to widen the road for full interstate-regulation shoulders or go without shoulders and extend the Zipper lane. While ratcheting up commuter rail frequencies to all 3 lines to maybe...just maybe...take a few cars off the Expressway. There is no killshot that lets you have eleventeen tracks and twelvety-eight lanes on the same footprint through Savin Hill.
Would it be cheaper and more feasible reconfigure the red line tracks north of JFK-UMass so that both branches serve the same platform and both branches serve Savin Hill? This way you still free up surface space for an additional CR track and shoulder or managed lane without the tunnel. Would also require track reconfiguration downstream as well to create a new branch split.