What machine did Leonardo da Vinci design to move without an external animal or human pushing it?

Leonardo da Vinci designed a self-propelled cart that could move without an external animal or human pushing it.

The design, drawn around 1478 to 1480, used two large driving wheels and a spring-powered mechanism concealed beneath the cart. The springs stored energy, while programmed control devices determined how far the wheels turned. A small front wheel helped guide the vehicle.

The cart was probably intended for theatrical performances or court spectacles rather than ordinary transportation. Its mechanism could make the cart travel along a predetermined path, producing a dramatic effect for spectators.

It was not an automobile in the modern sense: it had no engine, steering wheel, fuel system, or continuous power source. Reconstructions built from Leonardo’s drawings have shown that the basic mechanism can work, although scholars continue to discuss details of the original design and its intended use.