a safe travel → safe travel
a safe journey
a safe trip
The indefinite article, a, may be redundant when used with the uncountable noun travel in your sentence. Consider removing it.
Uncountable nouns (such as water, sand, or information) may or may not use a determiner, but they do not use the indefinite articles a or an.
Other determiners include the definite article (the), possessive adjectives (my, his, our), possessive nouns (Joe’s, mother’s), and quantifiers (some, any).
I’d like a milk with my dinner.
I’d like milk with my dinner.
I’d like a glass of milk with my dinner.
Depending on context, a noun can be either countable or uncountable.
We need a light in this room.
We need some light in this room.