What type of vehicle did Leonardo da Vinci design with concealed gears to move without horses?

Leonardo da Vinci designed a self-propelled cart with concealed gears to move without horses.

Drawn in the Codex Atlanticus, the cart used coiled springs to store energy. When released, the springs turned gears connected to the wheels, allowing the vehicle to travel forward. The design also included a steering system, although its exact operation is debated because the surviving drawings are incomplete.

The cart was probably intended for theatrical performances or court spectacles rather than practical transportation. It may have been able to follow a programmed route, making it an early example of mechanical automation. Leonardo did not build a modern engine-powered car; the machine relied on stored spring energy.

A full-scale reconstruction was built and demonstrated in the late twentieth century. Because the original design leaves some details uncertain, reconstructions differ in their interpretation of the mechanism.