Cainsworth Metrorail Map

So the basic premise of the setting that I'm making this map for is that a technologically advanced dieselpunk city became consumed by darkness. Basically this is "What if Gotham were consumed by Ravenloft?"

I'm going for a Dark Deco feel for this setting. If you don't know what I mean, it's the term coined by Bruce Timm and the other visual designers for Batman: The Animated Series. I'm going for a Metrorail map that encompasses all of the districts of this city. Each district has it's own thing going for it since the darkness happened. I am using Illsutrator for this project, but I have access to Photoshop, and Indesign as well.

I want to make a more elaborate map, but I've hit a wall. Is there a better way to make a city map, or does the idea I have work, and do I just need to keep going for it?