What was Leonardo da Vinci’s four-wheeled vehicle powered by coiled springs called?

Leonardo da Vinci’s four-wheeled vehicle powered by coiled springs was called the self-propelled cart.

Leonardo sketched the mechanism around 1478–1480. Large springs stored energy and released it through gears to turn the cart’s wheels, allowing the vehicle to move without an animal or person pushing it. Steering could be preset through a programmable mechanism.

The design was probably intended for theatrical use, such as entering a stage during a court performance. It was not an automobile in the modern sense: it had no engine, brakes, or continuous steering system.

A 2006 reconstruction in Florence demonstrated that the mechanism could work. Some historians also describe it as an early robot because its programmed movement could produce an action automatically.