Not sure if this still holds true, but at least up until a few years ago, only a commissioned law enforcement officer could direct traffic in Massachusetts. Consequently, if a construction company, road crew, etc. needed a flag man to turn a stop/slow sign, their only option was to hire an off-duty officer, usually at overtime rates to do a job a lot of teenagers on summer vacation do in other states.
K-9 trooper in doghouse?
My observations during my time in MA (refuse to say ‘mass’) the troopers on construction details just sat in their vehjcles.