I loved to vacation in Massachusetts. People were so nice up there.
I'll bet you vacationed in Mass during the summer or early fall, right? Between Halloween and Easter the weather gets really cold and nasty and dispositions turn dark. Even the kindliest looking little old lady one might encounter on the road up there during the dark months is liable to turn into a Kamakazi with snow chains when she sees a license plate from any state with a more temperate climate. Envy is a terrible thing.
Seriously--Mass drivers have long had a reputation within New England and beyond for being rolling road hazards no matter the season. My grandfather who lived in N.H. used to call Mass drivers either black buggers or Red Devils depending on the year (Mass used to change the color of its license plates every year alternating between black and sort of a maroon.)