Visible routes leaving each province are listed in the turn report. Route distances are rated in the number of days it would normally take a lightly loaded character, walking, to traverse them. Actual travel times may differ from the rated times. Characters overloaded with belongings will make slower progress. Horses usually speed progress, but over especially rough or treacherous terrain, they may actually slow travel because they must be led and managed.
Inventory is considered for the stack as a whole.
For instance, if one character possesses enough horses for every member of the stack, the stack may ride. Similarly, if one character is badly overloaded, but other characters have extra carrying capacity, they will assist their stackmate. Distribution of goods between units within a stack is irrelevant to movement. The units stacked beneath a moving character will move with the stack leader. If the unit issuing move is stacked beneath another character, he will first automatically unstack before movement begins.