The commuters from NH and ME have largely gravitated to the non-MBTA Lawrence garage; it's Zone 6, a short hop from 495 and you can park for $3 day rate with a train ticket. I have not checked for monthly deals, but the money saved from Newburyport's Zone 8 & $4/day is substantial. A couple of businesses on Rt. 1 are renting spaces to passengers too, and since Newburyport got the bike path finished a few years ago you can reach the depot entirely on sidewalks.
The bus park-n-ride by Rt. 113 is free and allows long-term parking. Some buses go via Logan, the rest direct to South Station. It's faster than the train unless Rt. 1 in Saugus is really wedged. The vernight parking makes it the only choice for air and Amtrak connections via South Station (provided you fit in the seats - C&J's pitch is way too short for people wearing 32" pant legs).
The busiest MBTA lot is actually in Newbury off Rt. 1, at the lower right corner of the picture. Parcel 1 is the 2nd least used lot, but it has frontage on Parker St. and could possibly get developer interest. However, Parker St. is sidewalk-less and there are properties that face Rt. 1 (by far the busiest road in the area) which have remained vacant or under-utilized for years. The other parcels are swampy land which is rather closer to the high tide elevation than I'd build on, post-Sandy and post-Irene. Newburyport has historically been agreeable to construction in swamp, but banks and insurance companies may have a clue by now.
My read: I don't know how the MBTA acquired this land, but if it came from the B&M it could have dated back to the original Newburyport RR in the 1870s - the former Newburyport/Eastern diamond is just above the label "Newbury" in the photo. Regardless, it isn't land they need, and won't have any affect on Portsmouth or parking, unless passenger counts double - the lot by the station building is much bigger than that on Parcel 1.
