The New York Times are currently running a fascinating series of articles about American speech throughout the years. The sixth part is a compendium of the vocabulary of the average 1962 traffic policeman, and contains some interesting definitions. It seems that quite a few are still in use today.
The specialist vocabulary came about as a result of the nature of the job, and the language is of a “highly confidential nature, being used almost exclusively on the job or in talking about the job, and usually in speaking to another policeman, to an insurance investigator, or to a traffic engineer”. A lot of it is quite coarse, too, due to it being part of a male-dominated profession.
Some of the vocabulary is amusing, some of it interesting from an etymological point of view, some of it is surprising that they needed a term for a particular person or situation.
Some examples from the article:
American taxpayer: A traffic law violator who loudly proclaims immunity because he is paying the policeman’s salary.
Bag case: A fatality in which a corpse is in such condition that it must be transported in a rubber bag or sheet.
Chinese fire drill: An accident scene of great confusion, such as a school bus or cattle truck upset.
Hunt owls: To have headlights so high as to blind other motorists.
Pajama badge: An overly zealous officer. “When he goes to bed, he even wears a pajama badge!”
Toe ticket: The last citation that a habitual violator receives-the identification ticket that is tied to the great toe in the morgue.
Volunteer: A motorist, usually a teenager of either sex, who deliberately commits a violation in front of a patrolman. No patrolman interviewed could offer any explanation for the conduct.