Related Clues:

• Sign outside a post office
• "Hit the brakes!"
• Exclamation to a pesky sibling
• Freight storehouse
• With 28-Across, like some traffic
• "Cut that out!"
• "Go no further!"
• Military supply station
• Train terminal
• ''Hold it right there!''
• Order on an octagonal sign
• Storage facility
• "Hold your horses!"
• Pickup line locale?
• "Go no farther!"