What type of vehicle did Leonardo da Vinci design to move without an external animal or human driver?

Leonardo da Vinci designed a self-propelled cart that could move without an external animal or human driver.

The late-15th-century design used coiled springs to store energy. When released, the springs drove the wheels through a system of gears and transmission components. A steering mechanism could set the cart on a predetermined path, making it an early example of programmable mechanical motion rather than a modern automobile.

The cart was probably intended for theatrical or ceremonial use, not ordinary transportation. Because the original object has not survived, reconstructions rely on Leonardo’s drawings and on interpretations of incomplete mechanical details. Tests of modern reconstructions have shown that the basic spring-powered concept can work, although the exact historical configuration remains uncertain. It is often called a robot or automobile in popular writing, but “self-propelled cart” is the more precise description of the Renaissance device.