Wouldn't it be best to have one mass market near the center on the map? You could always have two more on each side that of the map; a western and eastern market. Players can then use either the side markets or the center one to determine the inflation values if they should occur.
I made a quick picture of what I had in mind~
http://img.photobucket.com/albums/v223/Zumtil/Deli_traderouteidea.jpg
Legend:
Red: Area where central market town could be built.
Purple: Main trade routes.
Orange: Port town from Independence.
The only problem I see is the lakes around Green Dog. I'm new still and not sure if bridges are a possibility, or if it would be wise to even make a bridge that large. A ferry system could work, but that would require an almost 24/7 job, and that would be almost impossible...right? I guess you could just connect a road going East out of Green Dog that follows the tundra side at a three way intersection.
