Road tax (4)
I believe the answer is:
toll
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">road tax</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for toll that I've seen before include "Bridge or road charge" , "Be inclined" , "Ring - fee" , "Tax for using a service" , "Ring; levy" .)