What vehicle did Leonardo da Vinci design with a spring-powered mechanism to move without being pushed?

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

The drawing appears in Leonardo’s work on theatrical machinery and may have been intended to create a dramatic moving effect during a court performance. Two large springs stored energy, while a system of gears transferred that energy to the wheels.

The cart is often called an early automobile, but that description needs care. It had no engine using fuel and was not designed as a practical road vehicle for passengers. Its mechanism was closer to a programmable mechanical stage prop.

Researchers reconstructed the design in the 20th century and found that it could move when built according to Leonardo’s plans. Its steering and distance could be adjusted, showing that the concept involved more than a simple toy.