John, as someone who resides in the Seaport, yes there are hundreds of trucks per day. Believe me, they are rolling through at all times of day and overnight. They fly down Seaport Blvd overnight when there is no traffic.
Then BTD should do its fucking job for a change. This is not something the design of Seaport Blvd. needs to accommodate in any way, shape, or form. Trucks not serving businesses located directly on the streets of the Seaport are directed to use the Haul Road. Anything originating from the WTC should either be banging a left on W. Service Rd. or going through the rotary next to the Pavilion. If anything is barreling towards the Moakley at a high rate of speed to shortcut to 93, they're doing it wrong and it's Walsh's problem to rein in this city's many-decades rogue traffic enforcement agency instead of letting them invent yet another *wink-wink* look-the-other-way neighborhood "tradition".
Additionally, they can do what Massport does for Conley Terminal and many other major private trucking terminals do: make the trucking companies they contract follow a GPS-tracked route to control the riff-raff. For example, in Worcester you get your trucking company fined if you take a creative shortcut with a big rig out of the CSX intermodal yard instead of proceeding
immediately onto I-290; they have the instant paper trail to prove it in the form of that signal ping from the truck's dashboard. Now, that's not going to work for the small food/supplies delivery trucks and whatnot...but if these aren't small trucks and indeed are the big rigs from Marine Terminal, Harpoon warehouse, and the seafood warehouses making a mockery of creative shortcutting...absolutely, those companies can be ordered to ping the 'phone-home' signal to prove they're following the designated truck route. And face the consequences for non-compliance: fines, risk of losing their Massport contracts, sacking the private warehouses like Harpoon with fines for not policing their truck contractors, etc.
No reason it can't be done here when it's already done in this state on both the public and private sides of the port/terminal coin. Only more learned helplessness in the face of entrenched BTD corruption prevents them from regulating truck behavior on their own city streets.