Which Leonardo da Vinci invention concept was designed as a self-propelled vehicle?

Leonardo da Vinci designed a self-propelled cart concept powered by springs and mechanical gearing.

The drawing, made around 1478 to 1480, shows a three-wheeled vehicle with two large driving wheels and a smaller steering wheel. Coiled springs inside the driving drums supplied energy, while a system of gears transmitted that energy to the wheels.

The cart may have been intended for theatrical performances or court spectacles rather than transport. Because Leonardo’s drawing does not provide every construction detail, modern replicas have used different interpretations of the mechanism.

The vehicle is often called the world’s first robot or the ancestor of the modern automobile, but both descriptions need care. It had no engine and was not a practical road car; it was an ingenious programmable mechanical device capable of moving without someone pushing it.