The most common and most likely answer to this crossword clue is the 4 plus 4 letter word LONG HAUL
I've seen this crossword clue in The Daily Telegraph
L
O
N
G
H
A
U
L
More clues leading to the result LONG HAUL
Buddy explains!

The straight part
We know that "Journey" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case journey = long haul.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 LONG HAUL mean?
LONG HAUL noun- A long time; the long term; an extended period.
- A long distance
- (usually hyphenated) Travelling a long distance.
- To travel a long distance.
- To transport goods over long distances.