Possible Clues:

• Direct tax for part of policeman's job
• To indicate what one should do is a job for the police
• Regulation involving use of arms to target revenue
• Stops cars from working at concerts down the docks
• Traffic control by policeman for toy pundit
• Bringing members into play after signal failure
• That has the force at the crossroads
• The work the police have to do may bring things to a full stop