It's hard to impose order on systems that grow organically, like world-class cities. It's also hard to create a coherent public transit system in an imperfect society. That said, there are three seemingly small gaps in the Boston public transit system that continue to baffle and confound:
Why is it so hard to get from North Station to South Station? To be fair, this sort of thing is not uncommon in the world. Remember that time you thought you were leaving Brussels Nord but your train was really at Zuidstation? Yeah, that was a barrel of laughs.
If somebody asks me for such directions in the T, I just shake my head and tell them to head up the nearest stairs to the street and walk to take a cab. It's very likely that either method would be faster than a trip on the red and green or orange lines.
If you're trying to get from one half of the commuter rail system to the other, you may be able to cheat by using Back Bak or Porter Square, but if you're trying to take Amtrak from one side of Boston (for example, Maine) to the other (New York, for instance), you've got an awkward transfer on your hands.
Proposals for a North-South rail link have been kicking around for some time but remain in limbo at this time. This state of affairs is rendered all the more shameful now that South Station is the gateway to the Innovation District.
Why Can't You Get from the Red Line to the Blue Line? This has been a problem for ages, but it's a far more obvious gap now that Government Center is out of commission for a couple of years, meaning that State Street is the sole connection between the Blue Line and the rest of the system.
The prevailing thought here is to extend the Blue Line from Bowdoin to Charles Street to meet up with the Red line. With that done and Government Center back in business, you'd be able to get from any of the four main lines to any of the others directly.
The distance along Charles Street for a Red-Blue connector is about 1,500 feet. Tunneling the whole distance would cost a zillion dollars and require a new underground station beneath Charles. The estimable Amateur Planner has a modest proposal to connect the lines with a bit of tunnel and some elevated track to match up with the elevated Red Line at Charles. This would cost only half a zillion dollars, and I must say, looks like a whole lot better solution to me. Don't hold your breath.
Why is the Silver Line split at South Station? OK, this is far less serious a gap than the other two, but it's also far far easier to fix. the SL1 and SL2 that take you to Logan Airport, the Innovation District, and other points in South Boston. The SL4 and SL5 (don't ask what happened to the SL3) take you between Dudley Square and central Boston. SL1, SL2, and SL4 all converge at South Station, but to get from Dudley so the airport or Innovation District requires a transfer, which seems a pointless delay when the lines use the same vehicles and the same station.
The Red Line is not divided into two segments, Alewife-South Station and South Station-Braintree/Ashmont. Why should the Silver Line be so? Are the people who live in Dudley Square not interested in jobs in the Innovation District or air travel?
These gaps have been annoying, costly and inconvenient for years, but inertia on the North South and Red Blue connectors seems especially inexcusable in light of the city's current trajectory and the development of the MBTA system. The South Boston Innovation District is getting all kinds of emphasis, transit oriented developments like Assembly Row and North Point are on the rise. The Green Line Extension through Somerville may actually be happening. There's likely to be a Casino somewhere in the area soon. Why are all these new places to live and work not being connected better through the core of the city? If we want to avoid even more terrible car traffic, we'd better get digging. It's either a world-class city or it's not.