Local markets and travel times

In the dev talks there was mention that travel times wont be realistic but I wonder how local markets should emerge if everyone could just travel quickly to the central hub?

 

I know that the scale of the maps have changed since the Prototype (many times larger). So I am hoping that the world scale map is large enough that travel times across the continent are pretty slow without the use of the lunar rifts.

Also looking at the map there seem to be many bottlenecks, (mountain passes/tunnels rivers/bays/bridges)
One of the things that has been mentioned as an example, is the classic troll ambush at a bridge. This will pull you into an encounter hex and you will need to deal with the situation in order to pass. This could possibly be a large part of the travel time sink.