What vehicle did Leonardo da Vinci design to move by winding a spring before travel?

Leonardo da Vinci designed a self-propelled cart that moved by winding a spring before travel.

The cart appears in Leonardo’s Codex Atlanticus and is often described as an early programmable vehicle. Two large springs stored energy, while a system of gears transmitted that energy to the wheels. Cams helped determine the cart’s path and movement, making it more than a simple wheeled platform.

The design was probably intended for theatrical or ceremonial use rather than transportation. It may have been capable of moving forward and turning, although the original mechanism is incomplete and some details remain uncertain.

The cart is sometimes called a robot because it could perform programmed motion without a driver inside. That label is modern: Leonardo did not use the word “robot,” which was coined centuries later. Reconstructions have demonstrated that a working interpretation of the design is possible.