The commuter rail system has been extended (Worcester, Old Colony) and those relatively simple expansion ran into huge obstacles because of community and environmental concerns.
The red line doesn't go to Arlington because they didn't want it.
Thanks to NEPA. The problem is trying to find the right balance between letting NIMBYs dominate the conversation vs letting the state push through a transportation project that destroys neighborhoods (a la the original elevated artery). If the problem was easy to solve, it would have been solved by now.
Heh, I was going to respond "but Assembly Square is moving so fast". Then I read the Wikipedia and saw that it was declared blighted in 1979, and didn't actually see much improvement until 2005. Construction on the new mixed-use development has been moving rather well over the past two years though, after the IKEA legal tango was finally resolved.
Yeah, I already much prefer Assembly Row but it was useful from a bargain hunting sense.
They haven't extended the T since I think the 80s (Not counting those silver line buses). The green line extension is coming anytime now....
Massachusetts has a hard time getting stuff done, but it does seem to happen eventually (convention center, new garden, big dig).
Part of the problem is the lack of state (or county which barely exists here) control to push stuff through. The red line doesn't go to Arlington because they didn't want it. The garage at Ailewife station doesn't have enough spaces and the T doesn't have the money to expand parking to meet demand.
You are right, you can sit here all day and come up with improvements.