I created the complete map of the City through screenshots in-game, and I'd like to share the result, as it was quite useful for me.

At some point we find this note, belonging to Private Investigator Michael Sylar. Then we have to figure out his exact route through the City.

I did this for myself, and I'm sharing it here, as many of you want the logic behind an answer and not just "Insperctor Sylar ended up there".

The route starts at the green star (Lower East Park Lane).

The first column of the instructions is drawn in red, the second one in orange and the third in yellow.

The final destination is the blue star (Fargo Lane)

Hope it helps! :)