Wiktionary
coach box
n. The coachman's seat (on a horse-drawn vehicle)
Usage examples of "coach box".
The driver sitting on the coach box is younger, harder-faced than the gray-haired man who had brought them to Tyrsal's.
So he came with a big hat and spectacles and a coach box full of paper.
He lay against the leather cushions of the landau and laughed to himself, tossing a revolver high into the air and catching it again, his feet in their shining black boots crossed indolently on the coach box.