What Leonardo da Vinci invention is commonly called a self-propelled cart?

Leonardo da Vinci’s self-propelled cart was a spring-powered vehicle designed to move without being pushed.

Leonardo drew the cart around 1478–1480. Coiled springs stored energy, while gearing transferred that energy to the wheels. The steering system could be preset, allowing the cart to follow a programmed route rather than requiring a driver to control it continuously.

The machine is often described as an early ancestor of the automobile or robot. Those comparisons are useful only in a broad historical sense: the cart had no engine, no passenger cabin, and limited stored energy. It was closer to an ingenious mechanical automaton.

A reconstruction in the early twenty-first century showed that the design could operate, although scholars and engineers have examined how much of the mechanism was intended for practical travel versus theatrical display. It should not be confused with Leonardo’s armoured vehicle.