资料来源 : pyDict

交通警察

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Pointsman \Points"man\, n.; pl. {-men} (-men).
   A man who has charge of railroad points or switches. [Eng.]

资料来源 : WordNet®

pointsman
     n : a policeman stationed at an intersection to direct traffic