驭 originally pictured a hand (又) on a horse (马) — driving a chariot. It's the literary/classical form of 御 (yù) and survives mainly in compounds like 驾驭 (to drive/control) and 统驭 (to govern). In 《尚书》 the king 'drives the people like a frayed rein on six horses'.
马 is the horse radical and gives 驭 its literal image — a hand reaching for the horse to drive it. The verb extends to "control, command, manage" anything (驾驭, 驭手). Simplified 马 keeps its three-stroke compact form.
又 is the old hand-with-two-fingers pictograph. Beside the horse it shows the driver's hand grasping the reins — a compound-ideograph (会意) structure, not phono-semantic. No sound contribution; the meaning comes from horse + hand.
