Decree the road must be repaired in (6)
I believe the answer is:
ordain
'decree' is the definition.
(I know that ordain is a more specific form of the action decree)
'road must be repaired in' is the wordplay.
'must be repaired' is an anagram indicator.
'road' with letters rearranged gives 'orda'.
'orda'+'in'='ORDAIN'
'the' acts as a link.
(Other definitions for ordain that I've seen before include "Inroad (anag.)" , "Make a decree" , "Invest with priestly authority" , "Rule" , "Confer holy orders upon" .)