Leonardo da Vinci’s spring-powered vehicle is known as the self-propelled cart.
Leonardo designed the cart around 1478–1480. Two symmetrical leaf springs stored energy, while a system of gears transferred that energy to the wheels. A programmable steering mechanism, using pegs on a drum, could set the vehicle to follow a curved path. The design therefore combined propulsion, gearing, and limited automatic control.
The cart may have been intended for theatrical performances or court entertainments rather than transportation. Leonardo’s surviving drawings do not provide every construction detail, and historians have debated how the mechanism was meant to work. It was not powered by an engine or combustion system; its movement came from wound springs.
Modern replicas have demonstrated that the concept can move when built according to plausible interpretations of the drawings. Calling it an “automobile” can be misleading because it lacked a modern engine, but it is widely treated as an early self-propelled vehicle.