What vehicle did Leonardo da Vinci design to move under its own stored mechanical power?

Leonardo da Vinci designed a self-propelled cart intended to move using stored mechanical power.

The cart, drawn around 1478 to 1480, used springs to store energy. When released, the springs drove the wheels through a system of gears and related mechanisms. A steering arrangement could be set before the cart moved, allowing it to follow a predetermined path rather than requiring a driver to control it continuously.

The vehicle is often called a robot or an early automobile, but those descriptions can mislead. It had no engine, fuel system, or modern steering control. Its motion came from wound springs, much like a large clockwork mechanism. Reconstructions have tested versions of the design, although scholars debate some details because Leonardo’s drawing is incomplete.

The cart is distinct from Leonardo’s armored vehicle, whose movement is discussed in military-engineering contexts. The self-propelled cart is primarily a study in autonomous mechanical motion and programmable movement.