What self-propelled vehicle did Leonardo da Vinci design in a 1478–1480 sketch?

Leonardo da Vinci designed a self-propelled cart in a sketch dated approximately 1478–1480.

The cart was powered by coiled springs hidden inside its body. The springs turned the wheels through a system of gears, allowing the vehicle to move without being pushed by a person or pulled by an animal. Steering could be set in advance, so the cart followed a predetermined path rather than being driven like a modern automobile.

The design may have been intended for theatrical performances or court festivities. It is sometimes described as an early robot because it could perform a programmed movement, but it was not an autonomous machine in the modern electronic sense.

A working reconstruction was made in the early twenty-first century, confirming that the mechanism could operate when built according to the surviving drawing. Leonardo's cart therefore predates the automobile by centuries without using an engine.