Are these sentences correct:
1-This water is for you to drink on the road.
2-This water is for you on the road.
3-This water is for you while on the road.
Number one is clearest. Number two is not a natural English sentence. Number three seems to be an elliptical sentence, with "you're" understood, thus: "This water is for you while (you're) on the road."
I would prefer: "This water is for you to drink while you are on the road."