They would have to widen Cambridge street to 3-4 lanes in each direction around the area where the on/off ramps to the Pike come onto Cambridge to give extra space.
It's already 3 lanes in each direction. Trying to cut that down, since the on/off ramps are so dangerous. That's one of the reasons that MassDOT has made them perpendicular intersections.
1. Drop St. Mary’s St. Bridge
You do realize that approximately half of the BU student population crosses the St Mary St bridge to get to class, every day, right?
Actually, any proposal for an on/off ramp near BU is going to have to convince BU officials that you aren't going to kill students with this new injection of traffic...