Risk a ticket (5)
I believe the answer is:
speed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">risk a ticket</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for speed that I've seen before include "Rapidity - amphetamine" , "Rate of travel" , "Expedition" , "Rate of progress" , "Tempo - drug" .)