I'll buy that the answer is POTHOLE but how is this derived from the clue? I've seen two explanations. 1: it is an anagram of "the loop" but then what is "Traveller's" doing in the clue? 2: it is an anagram of Polo (traveller Marco) and "the" from between looping and loop in which case what is the instruction to treat these as an anagram - the clue no longer says "looping the loop" because "the" has been extracted as part of the anagram, and looping loop doesn't seem to make much sense.
Here's a wild thought. Perhaps it is an anagram of "the loop" (looping being the instruction to shuffle things around) with Traveller's giving "pot" (used for tripping) and depression simply giving "hole".
Help!