I am sure most of you already know about this resource, but just in case
The people at Standford have done a great job making a travel time calculator for the Roman Empire. You can find it here: orbis.stanford.edu/
Basically you decide on origin and destination, the month of travel (winter is slower, obviously), time (fastest, slowest or cheapest) and the mode of transort (road, river, sea, coastal ship) or combination thereof. And it returns the days between 2 points. Amazing and very useful as a travel time calculator under optimal circumstances. Medieval times would be slower, I guess, but it is still very useful. Seeing that it takes 1.5 days to travel between 2 points around my home that I do on a weekly basis in 1 hour is quite enlightening.
For those who are aware of such things, which coefficient roman - middle age would you use ? (road/river/sea separated if required to be accurate) on average?
I'm just trying to give my players different possibilies of roads, keeping the time real by the time. If I have no coefficient to use as Xavi said that was surely slower in the middle age, I'll just do +20% time.
Sea travel would be very similar, maybe a bit faster in the middle ages, roads are slower due to poor maintenance. I just wish this covered areas outside the empire... I have a Hibernian covenant in one game...
I have a spell that lets me and those Wizard's Communing in the spell teleport to the other end of the road (lengthwise), but it only works on roman roads, I use Orbis often to find where I can go, but we used it extensively before that as well. As a quick and dirty solution, you can also use Google maps and use walking speed, 8-10 hours a day is a good amount of walking to keep, 12 could also be done, but the combination of better and more roads and safer travel would make that unlikely.
What I find really usefull is the cost calculator. For example I have a covenant in Hibernia with an Hermes Portal to Venice. Now normally Venice gets it's flax from Egypt, with a transportation cost (according to Orbis) of about 2.2 Dinar per kg, or about 1 lb of silver for 100 lbs of flax. Now the transportation costs from Northern England (as close as this software gets) are about 4.5 dinar per kg. Flax is also an export for Hibernia, usually to England. Now we can export to Italy and should make about 1.5 dinar/kg or 1 lb of silver per 140 lbs of flax. So if we can move a bit under 3 tons of flax through the gate per year we should have a new lesser source of income...
