The most common and most likely answer to this crossword clue is the 9 letter word DROMEDARY
I've seen this crossword clue in The Daily Telegraph
D
R
O
M
E
D
A
R
Y
More clues leading to the result DROMEDARY
- Camel roamed freely in arid environment
- One with the hump dreary mod wound up
- Marry odd European, eccentric creature
- Like a desert in which roamed a southward moving 2
- One may be travelling dry road around Middle East
- Creature roamed freely in plain
- Departs city area in subtle desert transport
- Animal that’s roamed about in parched environment?
- Ungulate roamed freely with no rain around
- Desert traveller roamed haphazardly in arid setting
Buddy explains!

The straight part
We know that "transport" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case transport = dromedary.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DROMEDARY mean?
DROMEDARY noun- The single-humped camel (Camelus dromedarius).
- Any swift riding camel.