Charioteering (1, DEX, -2): A character with proficiency in this skill is able to
safely guide a chariot over any type of terrain that can normally
be negotiated at a rate one-third faster than the normal movement
rate for a character without this proficiency. For the movement
rates of chariots being drawn by animals, see the text on
“Movement of Land-based Vehicles” in the section on Encumbrance
and Movement. Note that this proficiency does not impart
the ability to move a chariot over terrain that it cannot traverse;
even the best charioteer in the world cannot take such a vehicle
into the mountains.