What transport device did Leonardo da Vinci design that moved by itself using springs and gear mechanisms?

Leonardo da Vinci designed a self-propelled cart powered by springs and gear mechanisms.

The cart appears in drawings made around 1478 to 1480. Large coiled springs stored mechanical energy, while gears transferred that energy to the wheels. Steering could be set in advance, allowing the vehicle to follow a programmed path rather than being continuously guided by a driver.

The device is often described as an early robot or the world’s first automobile. Those labels are useful comparisons, but they should not be taken literally: Leonardo’s cart had no engine, carried no passengers in its original design, and was probably intended for theatrical effects or court events.

Reconstructions have shown that the mechanism can move under spring power. Its importance lies in combining stored energy, transmission, and programmable steering in a compact machine.