You're on a motorway, approaching a working snow plough. Why should you stay behind it? You're on a motorway, approaching a working snow plough. Why should you stay behind it?

• Possible answers:

   
• A. It's illegal to overtake snow ploughs
• B. Snow ploughs are left-hand-drive only
• C. Your speed could cause snow to drift behind
• D. There may be deep snow ahead