What self-propelled machine did Leonardo da Vinci design to move without being pushed?

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

The machine, drawn around 1478 to 1480, used two large driving wheels and a pair of coiled springs. As the springs unwound, they powered the wheels through a system of gears. A steering mechanism allowed the cart to follow a programmed path, making it an early example of a programmable vehicle.

Leonardo may have intended the cart for theatrical performances or court spectacles rather than transportation. It could travel only a limited distance, because the springs stored a finite amount of energy. The surviving drawings do not reveal every construction detail, so modern replicas interpret some parts of the mechanism.

The cart is sometimes called a robot or the first automobile, but both descriptions need qualification. It had no combustion engine, and its automatic movement was mechanical rather than intelligent. Its importance lies in combining stored energy, gearing, and programmable steering.