Which Leonardo da Vinci design is an early concept for a self-propelled cart?

Leonardo da Vinci’s self-propelled cart is an early mechanical design for a vehicle that could move without being pushed continuously by a person or animal.

The cart was drawn with springs, gears, and a steering arrangement. Wound springs stored energy, while the mechanism transferred that energy to the wheels. The design may have been intended for theatrical or court entertainment, where a moving machine could create a striking effect.

It was not a motorcar in the modern sense. Leonardo had no internal-combustion engine, battery motor, or steam engine available for this project. The cart’s motion came from stored mechanical energy, much like a large clockwork device.

Modern reconstructions have shown that the concept can operate when built from Leonardo’s drawings, although scholars have debated details of the original mechanism and its exact purpose. The cart is also sometimes described as a robot because it could move autonomously for a limited distance, but it was a vehicle rather than a humanoid machine.