What self-propelled device did Leonardo da Vinci design for theatrical motion and transport experiments?

Leonardo da Vinci designed a self-propelled cart driven by stored mechanical energy.

The cart, often dated to the late 15th century, used coiled springs to power its wheels. Cams helped control the movement, allowing the machine to follow a predetermined path rather than being steered like a modern car. Leonardo may have intended it for theatrical displays, court entertainment, or experiments with automated motion.

The design was not powered by an engine, fuel, or electricity. Its energy came from springs that had to be wound in advance, making it closer to a large clockwork mechanism than to an automobile. A replica built in the 21st century demonstrated that the basic mechanism could move.

It is sometimes called the first robot or the first car, but both labels need qualification. It was an autonomous mechanical vehicle concept, not a road car for passengers, and the word “robot” was coined much later.