What Renaissance vehicle did Leonardo da Vinci design with springs to move without being pushed?

Leonardo da Vinci designed a self-propelled cart with springs to move without being pushed.

Leonardo’s drawing shows a three-wheeled vehicle powered by coiled springs. When the springs were wound, gears transferred their stored energy to the wheels. The cart could therefore move independently for a limited distance, although it was not an automobile in the modern sense.

The design was probably intended for theatrical performances or court spectacles rather than practical transportation. Its steering system also appears to have been arranged in advance, allowing the cart to follow a predetermined path.

The cart is often called the world’s first self-propelled vehicle, but that description needs context. It had no engine, fuel tank, or driver-operated controls. It was a spring-powered machine, closer to an elaborate mechanical stage prop than to a modern car. A working reconstruction was displayed at the 2006 Florence science festival.