What wheeled vehicle did Leonardo da Vinci design to move without a visible animal?

Leonardo da Vinci designed a self-propelled cart powered by clockwork-like springs.

The vehicle appears in drawings from the late 15th century and is often described as an early ancestor of the modern automobile. Coiled springs inside the cart supplied energy, while gears transferred that energy to the wheels. A steering mechanism also allowed the cart to follow a predetermined route.

Leonardo may have intended the machine for theatrical performances or court festivals, where a moving object could create a dramatic surprise. It was not a practical road vehicle in the modern sense, and its limited stored energy would have restricted its travel.

The cart is sometimes called a robot or automobile in popular accounts. More precisely, it was a programmable mechanical vehicle driven by stored spring energy, not an engine-powered car.