While overland travel has its perils when you go off the beaten path, taking the established travel routes has its cost as well. Nearly any man made or natural feature that facilitated travel is an ideal place to extract a toll from travelers. This includes obvious examples such as roads, bridges, towns, ports, or river crossings but even natural mountain passes could feature toll collection.
Collecting tolls is typically the business of the ruling governance, whether it is the emerging national governments in centralized states like France, local lords extracting a toll from traveling through their demesnes, guilds, bandits, strongmen, and anyone who thought they could get away with it. The question of legitimacy could often be raised when away from areas with a well established and strong rule. Even so, the collection of taxes and tolls could also be sold by rulers to other parties or delegated to the emerging class of bureaucrats, leaving behind a tangled mess.
The exact amount of tolls could vary widely; the following table lists a standard toll rate.
In general, the toll rates above should be applied for travel; however, rates may change as the world situation changes. As a rule of thumb, any wild deviation from these numbers should probably be reserved for a situation that would require role playing or as a part of a plot or adventure storyline. Deviations from these amounts can occur as a result of an increase in taxation and tolling, as a consequence of petty corruption to skim an extra coin, an illegitimate toll, or any fathomable plot hook. Otherwise, you will be role playing a lot of pointless toll collection.