21 apartments, retail space proposed for site next to commuter-rail station on Roslindale/West Roxbury line

to be extended. There are some cascading effects, but basically the NEC has a limited number of slots, and Needham trains take up a lot of them. Railroad signaling does not allow trains to run very close to each other, especially when there are higher speed trains in the mix (and yes, Amtrak runs 150 territory in Massachusetts). Step 1.0 is to electrify the fucking Providence Line (and the T could buy off-the shelf M8s that ConnDOT is purchasing, they've been running for years and have a good track record). Those trains would run faster than currently (100+ versus current top speed of 80) with much faster acceleration, so they'd clear the line sooner and free up some slots.

But that only buys you so much room (especially if taking 10 to 15 minutes of a run to Providence results in higher ridership). The obvious thing to do is to extend the Orange Line to Needham Junction. There are two tracks (and no grade crossings) to West Roxbury, although you would have to build some modifications for ADA accessibility at stations. Should be plenty of traction power with a major substation adjacent to the tracks in West Roxbury. A new station and turnback could be built by the VFW parkway, with the added benefit that this is only about 1000 feet (4 minute walk) from the VFW hospital there.

From there, you could use the existing single track to Needham, and run one train every 10-15 minutes. It's about 3 miles from VFW Parkway to Needham Junction. With a stop at Hersey, that's about 5 minutes (assuming you could run the new trains there at more than 40 mph). The right-of-way would allow for two tracks well to the east of Hersey, I think, so you could minimize this. Needham would have a slower ride in to Boston, but much more frequency. The single track would have to remain through Cutler Park, since widening the bridges there would be expensive, and widening the embankment through wetlands would be politically and technically infeasible. At rush hour, one in every four trains could run to Needham (perhaps even running express from Ruggles to Forest Hills), at other times, one in every two or three trains would run through.

As for Needham Center and Heights, a spur of the Green Line from Newton Highlands would suffice for service there (and could turn at Needham Heights). Grade crossings there make the Orange Line less feasible, although in theory it could be equipped with pans and run under the wire there. But that hook back makes more sense to run as Green Line from the D Line.

This is not a short-term project: you wouldn't want to think about it until after you get the new cars online in 2020ish and have a few years to break them in. But it's the kind of long-term planning the T and the state should be doing, but don't.

Well, when ever I had to take it, during rush hour, it was easily 40 minutes from Belgrade and the West Roxbury Parkway (35/36/37) - suppose that also include the time waiting at the stop for one of them to actually show up. Admittedly next bus has at least made that portion at bit better. Throw the Orange line on top, and you are looking at an hour of transit time that the commuter rail takes 15-20 minutes to do. Also that is what I meant - its the traffic of the Square an up Washington St that sucks - its fast to get to the square, takes forever to get through it, and then... forever again up Washington.

Sure, the walk from the Square is maybe 20-25 minutes (its 1.25 miles). Then its another mile to the Belgrade T stop, so 2.25ish mile walk is rather limiting for most people - and that is just to get to Forest Hills to then get the Orange Line. Kind of the point - walk to the Square to wait for a bus to then still have it in traffic up Washington St to Forest Hills, or maybe you are saying wait for the bus at Belgrade/West Roxbury Parkway, then get off in the Square and walk? I don't see how that is faster, either, since you are already on the bus - although I suppose a bit healthier.

All of the Needham Line stations have parking, often under-utilized.

I agree, this also needs to happen. The city is actually working on this through Vision Zero and other initiatives. The thing is, we have to do all this simultaneously. Waiting on transportation reform before we build the projects that require the effort leads to no reform happening. We have pressures on housing and need to respond. If the city drops the ball on transportation pressures, that does not mean we suddenly no longer need housing.

There is no transportation/parking master plan that addressed population growth and traffic congestion.

I'm not sure if you intend it this way but this is actually a straw man argument. There is no silver bullet that will allow more people to own and use cars in the city without traffic getting worse. The two thing that is known to work among city planners around the world are building less parking and charging people a fee for driving their car through the city. If parking is scarce, fewer people will own cars. The UNAVOIDABLE caveat is that many of the people who already live here are going to find it much harder to park (but that's a good thing, because hopefully then some of them will choose to get rid of their cars, too).

There are some things we can do to streamline the process, like charging a LOT more for parking so that those who truly need to own a car are still able to find a parking space, but there is NO WAY to have copious free parking in a prospering, walkable city without either discouraging car ownership (through cost and scarcity of parking) or pricing out all but the richest people.

If you make the zoning so restrictive, as most of Roslindale's is save for the Square, you end up with the current situation - existing homes rising quickly to very high price points that only the wealthy can afford. So pick which you prefer.