What machine did Leonardo da Vinci design to move on its own using springs?

Leonardo da Vinci designed a self-propelled cart powered by coiled springs.

The design appears in drawings from around 1478–1480 and is often described as an early programmable machine. Two large springs stored energy and drove the cart’s wheels through a system of gears. A steering mechanism could be set in advance, allowing the vehicle to follow a planned path rather than being continuously controlled by a driver.

The cart may have been intended for theatrical performances at court, where a moving mechanical object could create a dramatic effect. It was not an automobile in the modern sense: it had no engine, fuel system, brakes, or steering wheel.

A full-scale replica built for a 2006 Italian television documentary demonstrated that the mechanism could work after details were reconstructed. The vehicle is therefore notable as a practical mechanical concept, while its exact original purpose remains uncertain.