I'd call around when travelling (6)
I believe the answer is:
riding
'travelling' is the definition.
(I know that riding is a type of travelling)
'i'd call around' is the wordplay.
'call' becomes 'ring' (telephone call).
'around' means one lot of letters goes inside another.
'id' going into 'ring' is 'RIDING'.
'when' acts as a link.
(Other definitions for riding that I've seen before include "Going cycling, perhaps" , "being carried" , "Third Division" , "Establishment teaching equestrian skills" , "Horsemanship - once a third part of Yorkshire" .)