What Leonardo da Vinci design used a spring-powered mechanism to move without a rider or animal?

Leonardo da Vinci designed a self-propelled cart as a spring-powered vehicle that could move without a rider or animal.

The design, recorded in Leonardo’s notebooks around 1478–1480, used large springs concealed inside the cart. Those springs were wound before the vehicle was released, and gears transferred their stored energy to the wheels. A steering system allowed the cart to follow a preset route rather than simply rolling straight ahead.

The machine is sometimes called Leonardo’s automobile, but it was not an automobile in the modern engine-powered sense. It had no combustion engine, and its power came from wound springs. Its mechanism may have been intended for theatrical performances or court spectacles, where a moving object could create a dramatic effect.

Modern reconstructions have shown that the design can work. The cart is important because it combines stored mechanical energy, gearing, and programmable movement centuries before motor vehicles became practical.