What transport machine did Leonardo da Vinci draw with four wheels and a wound-spring propulsion system?

Leonardo da Vinci drew a self-propelled cart with four wheels and a wound-spring propulsion system.

The cart appears in Leonardo’s late-fifteenth-century engineering studies. Two symmetrical springs were intended to store energy, while a system of gears controlled the release of that energy to the wheels. Steering could be set in advance, allowing the cart to follow a predetermined path rather than being driven by a rider.

The machine is sometimes called Leonardo’s automobile, but that modern label can mislead. It had no internal-combustion engine, fuel system, or driver’s controls like a modern car. It was better understood as a clockwork vehicle or mechanical stage device. Scholars have also connected it with theatrical displays and ceremonial entertainment.

A reconstruction at the Museum of the History of Science in Florence helped demonstrate that the mechanism could move when built with the essential features of the drawing. Its significance lies in programmable motion, not in being a practical road car.