What self-propelled cart did Leonardo da Vinci design to move without horses?

Leonardo da Vinci designed a self-propelled cart that could move without horses or a person pushing it.

The design, usually dated to around 1478–1480, used two large driving wheels and a pair of tightly wound springs concealed beneath the cart’s body. As the springs unwound, they supplied the stored energy that turned the wheels. A steering mechanism allowed the cart to follow a preset path, making it more like a programmable theatrical vehicle than a road car.

Leonardo may have intended it for court entertainments and stage performances. The machine did not contain an engine or fuel system, so it was not an automobile in the modern sense. Its movement was limited by the energy stored in its springs.

The cart’s function was reconstructed and tested in the 20th century. Because Leonardo’s original drawings did not show every mechanical detail, reconstructions involve interpretation. Its importance lies in combining stored mechanical power, steering, and repeatable motion in one compact Renaissance design.