Road speed to be changed, which is criminal (9)
I believe the answer is:
desperado
'criminal' is the definition.
(desperado is a kind of criminal)
'road speed to be changed' is the wordplay.
'to be changed' is an anagram indicator.
'road'+'speed'='roadspeed'
'roadspeed' is an anagram of 'DESPERADO'.
'which is' is the link.
(Other definitions for desperado that I've seen before include "reckless type" , "Reckless outlaw" , "Bravo" , "Reckless person" , "Bandit, outlaw" .)