I agree that there are higher priorities. But what GLXX to Porter provides is CAPACITY and Network Redundancy -- the ability to offload some Red Line traffic through Cambridge. Red is pretty maxed out in the core Cambridge stops.
www.cambridgeday.com
Can't. The wheel profile on LRT is different from the wheel profile on a RR, so they can't coexist at full speed on the same track without much-heightened derailment risk. Plus there's no FRA-compliant tram-trains in existence, so it's impossible on crashworthiness. Finally, as @sneijder notes, rapid transit's 600V DC electrification is incompatible with commuter rail/Amtrak's 25kV AC electrification.
It's just part of the time-honored Mass tradition of having bridges look like they're about ready to fall apart.
What?
What I’d understood from some other discussions in the forums is that GLX further to Kent St. or even Porter is doable but it looks like the same ROW or larger up until just East of Waltham. I’m definitely missing something here and wondering out of curiosity where the restrictions are or if it’s the whole segment of the line that doesn’t have enough ROW.
That’s the primary big rolling stock/infrastructure thing that makes this very much a ‘crazy transit pitch’. I know it’s possible to have two different voltages of caternary offset from each other on the same line but that requires very unique trains making that tram-train option just a thought.
From what I was reading the issue is more train on tram tracks than the other way around. In the case of trams on train tracks the issue is curve speed and hunting oscillation correct? Then if trams remain within their designed speed at which hunting oscillation isn’t an issue then they’d be safe? If the trams are designed for 50mph like the current Green Line trolleys that should be significant enough for decent service on that stretch. Disregarding all the signaling and legal barriers it should be physically possible to operate safely.
The ROW was quad-track to Belmont Center, tri-track to the Central Mass split (excepting the Waverley station cut, which was a 1955 grade crossing elimination). It's widenable to 4-tracks between Belmont Ctr. and the Central Mass by doing some of the same retaining wall work that went into GLX-Medford, but to get to Waltham Center and 128 the Central Mass must be reactivated to carry the Fitchburg RR because the ROW through Downtown was only ever 2-track.
The speed restrictions of trying to safely interoperate are painful. Like, 10 MPH or less. It would never work in a practical application.
this ties perfectly in with the conversation in previous posts. I just have no idea what other developed country would let this happen... for a bike path.
