Heading north from depots, substitute coaches pick up here? (3,4)
I believe the answer is:
bus stop
'coaches pick up here?' is the definition.
(place where coaches pick up passengers)
'heading north from depots substitute' is the wordplay.
'heading north' is a reversal indicator.
'from' indicates a hidden word.
'potssub' is hidden in the letters of 'depots substitute'.
'potssub' back-to-front is 'BUS STOP'.
(Other definitions for bus stop that I've seen before include "Perhaps request" , "Where to get public transport" , "One could get carried away from here" , "one expects a certain number here" , "Film" .)