MBTA3247 wrote:Why not both? When I was plotting my BLX idea out, Watertown Center via Beacon Yards/West Station, HBS/North Harvard St & Western Ave, the new Arsenal redevelopment, and Arsenal St seemed like another logical extension that would probably be 2/3 cut+cover, 1/3 deep bore. Unlimited money allowing, of course...Bramdeisroberts wrote:Though if you're not swallowing the D, then I'd build it down Brookline Ave to Longwood, with a simple stub station at Brookline Ave and Longwood Ave.I would offer an alternative routing beyond Kenmore: extend the subway part or all of the way under the former A line, to further relieve pressure on the B and 57 bus.
That said, if there is any T line that lends itself to deep boring, the Blue Line, with its comparatively tiny loading gauge, would be it, speak nothing of its ability to handle tight turns better even than an IRT trainset can. Thinking of it as a potential "T-Tube" is something that doesn't get done nearly enough, imho.