Which Leonardo da Vinci invention is considered an early example of a self-propelled vehicle?

Leonardo da Vinci’s self-propelled cart is considered an early example of a self-propelled vehicle.

Leonardo sketched the cart around 1478–1480. Unlike a normal wagon, it was designed to move without an animal pulling it. Coiled springs stored energy, while a system of gears and cams transferred that energy to the wheels and controlled the cart’s movement. The steering system could be set before the cart began moving.

The cart may have been intended for theatrical performances or court displays rather than transportation. It was not an automobile in the modern sense: it carried no engine, fuel system, or driver. In 2006, researchers at the Museo Galileo in Florence built a working reconstruction, showing that the basic mechanism could operate when made according to the surviving drawings.