The Alewife interchange used to be a rotary, before the Red Line extension and the construction of Alewife Station. There was a horrible road construction project there that seemed to last around five years, and now the former site of the rotary is occupied by an intricately-signaled Y-intersection whose three arms are Route 2 to the west, and the Alewife Brook Parkway to the northeast and south. It's made worse by the decision to route an exit from the Alewife Station parking complex directly into the heart of this intersection, to allow commuters to get directly onto Route 2 westbound.

Matt, do you know the nightmare that is Concord Ave/Leonard St/Common St/Stone Bridge at Belmont Center? I started to try to describe it and gave up.