I don't really see where the lanes are or anything...
Usually when I make maps like this, I draw out the layout and such first on the map using lines of random terrain to help visualize how everything will fit into the space. Whatever, show us more when you've got more of the terrain done.
Hmm... You're right, they aren't much visible. From game view though, they are visible. When the terrain is done, I'll draw the lanes with something in paint...