Heads up!
Be sure to get and keep a dated parking card/pass/ticket at the toll plaza ...
OT: It is a good idea when paying cash to get a receipt at regular toll plazas too, for example on Florida's Turnpike. At many locations the only cash toll booths are off to the side on what looks like an exit ramp and only folks with an electronic transponder honored by that toll agency may use the main lanes (EZ-Pass, I-Zoom, and Fast Pass , er, Fast Lane) do not work in Florida).
There was a flashing sign on the Mass. Turnpike reading "Free Fast Pass" to advertise their transponder program.