Hi John H8,
Thanks a lot for your answer.
As I see it veloci cannot discribe "noi" (we) as "we" could be for example two very old, very slow people, but they travel fast. So I would say veloce discribe "viaggiamo".
If I translate the sentence into my own native language danish, we would never put the word veloce in plural as it is used in this sentense.
It would make no difference if the sentense started with "Noi viaggiamo ..." or "Io viaggio ... the word "veloce" would be the same - without conjugation.
But then again - that might not be true in italian.
By the way, your inputs are very much appreciated.