Can one also say «Ποιος δρόμος είναι αυτός;»?
You can say Ποιος δρόμος είναι αυτός; without "ο" before δρόμος.
Ποιος είναι ο δρόμος αυτός;?
Ι was wondering the same thing. I think that should be accepted, but I see you are still waiting for an answer, and it is still refused.
Can you say - τι δρόμο είναι αυτό ?
No. Δρόμος is a masculine word. Which (masculine) = ποιος. Τι = what or what kind of.
If you wanted to ask "what kindof road is this?" you could say "τι δρόμος είναι αυτός?" but don't forget the ς
Can one say Ποιος ειναι αυτος ο οδός?
Οδός is feminine, and as such you must say ποια είναι αυτή η οδός;