What machine did Leonardo da Vinci design to make a cart move without being pushed or pulled?

Leonardo da Vinci designed a self-propelled cart that could move without being pushed or pulled.

The cart appears in drawings from the Codex Atlanticus and is usually dated to around 1478–1480. Its movement was supplied by coiled springs hidden inside drums. When released, the springs drove the wheels through a system of gears, much as a wound clock mechanism stores and releases energy.

A steering mechanism could be set before the cart began moving, allowing it to follow a predetermined route. This made the design especially suitable for theatrical displays or ceremonial events rather than ordinary transportation. It was not powered by steam, electricity, or an internal-combustion engine.

Modern replicas have shown that the concept can work, although the surviving drawings leave some details open to interpretation. Calling it an automobile is misleading: Leonardo’s cart had stored mechanical energy and limited programmed motion, not continuous self-powered travel.