What self-propelled device did Leonardo da Vinci design to move without being pushed by a person or animal?

Leonardo da Vinci designed a self-propelled cart to move without being pushed by a person or animal.

The cart used coiled springs as its power source. When the springs were wound, they released energy through a system of gears, allowing the wheels to turn. Steering could be set in advance, so the cart followed a predetermined route rather than being controlled continuously by a driver.

Leonardo probably intended the machine for theatrical or ceremonial use, possibly to surprise guests at court. It was not an automobile in the modern sense: it had no engine, brakes, steering wheel, or passenger cabin. Reconstructions have demonstrated that the mechanism can move, although surviving evidence does not establish every detail of the original construction. The cart is sometimes called the first self-propelled vehicle, but that label is a modern comparison rather than a title Leonardo himself used.