Leonardo da Vinci’s self-propelled cart had three wheels.
Leonardo designed the cart around 1478–1480, making it one of the earliest known concepts for a programmable or self-moving vehicle. Two large rear wheels were powered by coiled springs, while a smaller front wheel helped steer the cart. A system of pegs and stops could be arranged to determine the distance and direction of travel.
The cart was not an automobile in the modern sense. It had no engine, fuel tank, or driver’s controls. Instead, its stored mechanical energy came from springs wound before operation. The mechanism may have been intended for theatrical performances, perhaps to create a moving effect during court celebrations.
The original drawing does not reveal every construction detail, so modern replicas have used different interpretations. In 2006, researchers and engineers built working reconstructions based on Leonardo’s surviving sketches. The three-wheel layout is the key identifying feature, separating the cart from his later humanoid automaton designs.