What type of vehicle did Leonardo da Vinci design with a conical gear mechanism to move without horses?

Leonardo da Vinci designed a self-propelled cart with a conical gear mechanism to move without horses.

The cart appears in Leonardo's studies from the late 15th century. Its propulsion system used coiled springs, somewhat like large clock springs, to store energy. Gears transferred that energy to the wheels, while a steering mechanism could be set in advance. This made the cart a programmable vehicle for its time: it could travel along a predetermined route rather than being guided continuously by a driver.

The design was probably intended for theatrical or ceremonial use, possibly to create a dramatic moving effect at a court event. It was not a motorcar in the modern sense because it had no internal-combustion engine and depended on stored mechanical energy.

A full-scale reconstruction displayed at Clos Lucé in France demonstrated that the mechanism could work when built according to Leonardo's principles. The cart is sometimes called the “Leonardo car,” but “self-propelled cart” is the more precise description of the Renaissance machine.