Criticise curtailment of highway leading to another (5)
I believe the answer is:
roast
'criticise' is the definition.
(I've seen this before)
'curtailment of highway leading to another' is the wordplay.
'curtailment of' means to remove the last letter (to curtail is to cut short).
'highway' becomes 'road' (I've seen this before).
'leading to' says to put letters next to each other (some letters go before or lead others).
'another' becomes 'st' (I can't explain this - if you can you should give a lot more credence to this answer).
'road' with its last letter removed is 'roa'.
'roa'+'st'='ROAST'
(Other definitions for roast that I've seen before include "Get very warm" , "pan" , "Be uncomfortably hot" , "Large piece of oven-cooked meat" , "Cook; criticise" .)