Staff touring area wrong to limit good advice to motorists (4,4)
I believe the answer is:
road sign
'advice to motorists' is the definition.
'staff touring area wrong' is the wordplay.
'staff' becomes 'rod' (I've seen this before).
'touring' is an insertion indicator (touring can mean going round).
'area' becomes 'a' (maths abbreviation).
'wrong' becomes 'sign' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'rod' placed around 'a' is 'road'.
'road'+'sign'='ROAD SIGN'
'to limit good' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for road sign that I've seen before include "'It informs or instructs highway users (4,4)'" , "Roundabout ahead or T-junction, say" , "Stop or Yield, say" , "Info for drivers" , "Perhaps stop" .)