What transportation device did Leonardo da Vinci design with two large wheels and a winding mechanism?

Leonardo da Vinci designed a self-propelled cart powered by wound springs and controlled by a steering mechanism.

Drawn in the late 15th century, the cart is often described as an early ancestor of the automobile. Two large springs stored mechanical energy, while wooden components transferred that energy to the wheels. A programmable system using pegs could determine how the cart turned, allowing it to follow a preselected path.

The surviving drawing does not show every detail needed to reconstruct the machine, so modern interpretations have tested different arrangements. In 2006, an Italian team built a working model based on Leonardo’s sketches and demonstrated that the basic concept could move.

The cart was probably intended for theatrical or ceremonial use rather than ordinary travel. It may have been designed to create a dramatic effect at a court event. It had no engine, fuel system, or modern transmission, but its stored-energy drive and steering ideas were unusually sophisticated for the period.