What Leonardo da Vinci invention is a four-wheeled vehicle often called the first robotic car?

Leonardo da Vinci's four-wheeled vehicle is commonly called the self-propelled cart.

Leonardo designed the cart around 1478–1480. It was powered by coiled springs hidden inside its body, with toothed gears transmitting the stored energy to the wheels. Steering could be set in advance, allowing the cart to follow a predetermined path rather than being guided continuously by a driver.

The design appears in drawings from the Codex Atlanticus. It was probably intended for theatrical performances or court pageants, where a moving object could create a striking effect. The machine was not an automobile in the modern sense: it carried no engine, had no onboard controls, and could travel only for a limited distance.

The cart is sometimes called Leonardo's robot or the first robotic vehicle because it could move automatically along a programmed route. Its exact original configuration remains debated, since the surviving drawings omit some construction details. A working reconstruction was made for a 2006 exhibition at the Museo Galileo in Florence.