Which Leonardo da Vinci invention is a four-wheeled cart that moves without a person or animal pulling it?

Leonardo da Vinci’s self-propelled cart is a four-wheeled vehicle designed to move automatically without a driver or draft animal.

Leonardo sketched the cart around 1478–1480. Coiled springs inside its body stored energy, while a system of gears and cams controlled the wheels and steering. The mechanism could be preset to follow a short route, making the cart an early programmable machine rather than a true engine-powered automobile.

A modern reconstruction by the Institute and Museum of the History of Science in Florence demonstrated that the design could work. The cart is sometimes described as a robot or theatrical automaton, but Leonardo did not provide evidence that it carried passengers or traveled long distances. Its importance lies in combining stored mechanical energy with automatic control.