The definite article 'ο' is generally 'τον' in the accusative case, except that the movable / ephelcystic letter 'nu' in 'το(ν)' is dropped before the letter 'δ'. In Greek this is called 'νυ εφελκυστικό'.
You may see it written sometimes as '*τον δρόμο' to make it emphatically explicit that 'δρόμο' is the accusative case of 'δρόμος'. This would have been ᾽῾τὸν δρόμον" in Ancient Greek. So retaining the letter 'nu' is conservative. But, you typically won't hear native speakers enunciated the 'nu' there in connected speech. The following δέλτα absorbs the νυ, so to speak.
Have a look at this video for a nice explanation: https://youtu.be/8hvhWx7fIDM.
Also, check out my attempt at explaining the rule in this Reddit thread: https://www.reddit.com/r/GREEK/comments/c5oluv/since_both_τον_καφέ_and_το_καφέ_or_τηντη_ζωή_seem/es3dyeg?utm_source=share&utm_medium=web2x
"ο δρόμος" is masculine. I don't know where you saw it as neutral. Perhaps, seeing the use here: "Το αγόρι βρίσκει το δρόμο." gave you that impression. It is not neutral but masculine accusative...see here:
If you saw "δρόμος" as neutral please tell us where that was.
Here are the rules for the use of the final v as taught in Greeks schools today.
Some words sometimes retain the final v or lose the final v.
-the article την
-the personal pronoun third person αυτήν, την
-the particles δεν and μην
These words retain the final ν when the word that follows begins with a vowel or with the consonants κ, π, τ, the double consonants μπ, ντ, γκ, ξ, and ψ. (ξ and ψ are considered double).
For example την είδα, I saw her, την κοπέλα, the girl, την ντουλάπα, the cupboard, δεν ξέρω I don’t know
Therefore, these words lose the final ν when the following words begin with one of the other consonants: β, δ, γ, φ, θ, χ, μ, ν, λ, ρ, σ, ζ.
For example τη δασκάλα, the teacher (feminine), τη θυμήθηκα, I remember her, δε θέλω I don’t want
In written form, the final ν is always kept on the masculine singular definite and indefinite articles (τον the, έναν a/an one )
For example τον νέο (άντρα) the young when used for the masculine word “man” but το νέο (είδηση) the new message, The final n is always used for the article των, the personal pronoun **αυτόν, τον, and σαν
For example των θαλασσών, the seas, αυτόν θέλει, he wants, τον φώναξε, I called him, σαν λύκος like a wolf