What transport machine did Leonardo da Vinci design to move without being pulled by animals?

Leonardo da Vinci designed a self-propelled cart that could move without being pulled by animals.

The cart used two large driving wheels and a system of coiled springs concealed inside drums. When the springs were wound, their stored energy could turn the wheels and propel the vehicle for a limited distance. A steering mechanism also allowed the cart to follow a predetermined route, making it an early example of programmable mechanical movement.

Leonardo drew the design around 1478–1480, but he left no evidence that it was built in his lifetime. Modern reconstructions have shown that a working version can be made from the surviving drawings, although details such as the exact spring arrangement require interpretation. The cart was not a car with an engine, and it could not travel indefinitely. Its importance lies in combining stored mechanical energy, motion, and planned steering in a compact Renaissance machine.