Traffic restriction may dispel time wasting (5,5)
I believe the answer is:
speed limit
'traffic restriction' is the definition.
'speed limit' can be an answer for 'restriction' (I have seen 'legal restriction' mean 'speed limit' so perhaps 'restriction' could also mean 'speed limit'). I am unsure of the 'traffic' bit.
'dispel time wasting' is the wordplay.
'wasting' is an anagram indicator (waste can mean to destroy).
'dispel'+'time'='dispeltime'
'dispeltime' is an anagram of 'SPEED-LIMIT'.
'may' is the link.
Can you help me to learn more?
(Other definitions for speed limit that I've seen before include "maximum rate by law" , "Legal cap on drivers" , "permitted maximum velocity?" , "rate cap" , "Maximum MPH allowed on a particular road" .)