What vehicle did Leonardo da Vinci design that is often described as an early self-propelled cart?

Leonardo da Vinci designed a self-propelled cart that is often considered an early ancestor of the modern automobile.

The cart appears in drawings from the late fifteenth century. Unlike a normal wagon pulled by an animal, it was intended to move through stored mechanical energy. Coiled springs inside the cart powered the wheels, while a steering mechanism controlled its route. The design may have been intended for theatrical or ceremonial use, where an unmanned vehicle could produce a dramatic effect.

The cart was not an automobile in the modern sense. It had no engine, fuel system, brakes, or passenger cabin, and its exact operation had to be reconstructed from incomplete drawings. In 2006, researchers at the Institute and Museum of the History of Science in Florence built a working replica based on Leonardo’s plans.

A common mix-up is to call it a steam car. Leonardo’s cart depended on spring power, not steam or an internal-combustion engine. Its importance lies in combining propulsion, steering, and mechanical transmission in one compact design.