What was Leonardo da Vinci’s self-propelled cart designed to do?

Leonardo da Vinci’s self-propelled cart was designed to move without being pushed.

Leonardo sketched the vehicle around 1478–1480. Its movement came from coiled springs hidden inside the cart, rather than from a person pushing it or sitting inside to power it. A system of gears transmitted spring energy to the wheels.

The cart also included programmable elements. Pegs placed on parts of the mechanism could control steering, allowing the vehicle to follow a predetermined path. This made the design resemble an early mechanical automaton as well as a transport device.

The cart’s exact purpose is uncertain. It may have been intended for theatrical displays at court, where mechanical surprises were popular, rather than for practical road travel. Modern reconstructions have demonstrated that the basic mechanism can work, although interpretations differ over details of the original design.