I've downloaded it in 300 dpi, so it should be legible. This is a section of central France and southwestern Germany. It shows the relationships between 118 markets (though obviously not with those markets off page). Some of these relationships are roads (brown lines), but some are rivers (blue lines). In the latter, the arrow indicates the flow of the river. Because of the flow, Speyer in Germany is 1.2 days away from Strasbourg but Strasbourg is 1.9 days away from Speyer.
There are also places in grey that are convenient way-stations between markets that made mapping this easier. Rather than have 12 cluttered and inconvenient lines between Troyes, Chalons-sur-Marne, Metz and Nancy, it is easier to just show how routes between them pass through Vitry-le-Francois and Commercium.
The latter is, incidentally, the old name for Commercy, a city in Lorraine. I post the French link because it has way, way more information than the English Wikipedia page (I so love google translate - google can take over the planet so long as google translate remains in existence). Believe me, the town is named very well. It may not be self-evident for many from the map above, but the routes are based on the shortest distances between individual places, accounting for both mountain passes in Europe and difficulties of getting up over high elevations. As such, the most southern land route between Italy and central France runs up from Turin to Aoste, thence into Switzerland at Lausanne and from there, to Besancon in Burgundy.
This makes Burgandy incredibly important to land trade in Europe. It explains why the first medieval fairs took place there in the 14th century, it explains why both Charles the Great and Spain fought like demons to control it, it explains why it was famously the richest county in Europe, it explains why Germany and France fought over Alsace and Lorraine for centuries (both together are the gateway from one half of Europe to the other). Commercium as the name of the city describes exactly the presence of pure, unbridled wealth passing through those cities between Nancy and Troyes (which was said to be the size of London in the 15th century). This power didn't go away until long sea voyages around Africa put the balance of trade onto the Atlantic seaboard - making Amsterdam, Rotterdam and Antwerp an even bigger crossroads between the Atlantic and the Rhine valley, where Burgundy/Lorraine/Alsace still served as a collection point for central Europe.
Anyway, regarding the transport section of the tutorial, this is my personal method for keeping track of how far each market is away from all others. I do have an excel table that helps me calculate any single market here from every other market (I have over 900), but I'm going to forego writing about that just now. I'll put it up on the wiki soon - but I worked my ass off yesterday and I'm tired.
Heh, heh, heh. My feet and my hands are now begging people to consider making a donation to my jumpstarter. I know, I know, we're all working hard. But if I can get enough donations I can ask for less hours at work and spend more time focusing on writing my book, so I'm still asking for support.
21 days until I will be posting my book preview. A $25 donation is needed to see that.