One Day. It is 448 B.C. Darn how will we make it to Medieval, that is where it is going to get really fun.
We do have to remember that these roads are across lands that (I personally know all too well) are home to barbarians who would very much like to steal our shit. It'll be a bitch to police a road all the way from Rome to Danzig. Not to mention build it.
Rome: Perhaps we take the land first, to secure it, and then make the route. Otherwise the caravans would never survive.
This. Around this time period, Europe was much more heavily forested than it is today, roads will be rough and dangerous.
It can't be super effective when it's used outside of battle, you horrible person. A single city to defend all trading routes across Europe?
King Christian accepts the proposal, IF it can get Aarhus some bronze and/or iron. And we shall wait for the map to be updated.
The sea is the Baltic is relatively unpirated and you should be able to easilly trade with Denmark, Sweden, and Poznan. A road from Scythia to Poland shouldn't be too hard to make because it's just steppes and plains, it's bandits we should be worried about.
Perhaps all the members of the Trade Pact could pool their resources into creating a police force specifically dedicated to policing the roads? Kind of like the Knight's Watch.
Map update: Added Danzig. I'm off now. EDIT: When tomorrow starts for you, choose what you want to colonize.