The most common and most likely answer to this crossword clue is the 8 letter word EUROSTAR
I've seen this crossword clue in Financial Times
E
U
R
O
S
T
A
R
More clues leading to the result EUROSTAR
- For which tours are organised?
- Train someone who’d like to make it big in the US, too?
- With which tours are devised?
- For train, affected routes are detailed
- Surrogate on the move wanting good train service
- Rail service tours are all over the place
- Train service, where routes abroad on a railway starting out
- Wasted rates involving our renewed travel service
- Old celebrity on French street, returning for train
- Train routes are endlessly reorganised
Buddy explains!

The straight part
We know that "travel service" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case travel service = eurostar.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.