What kind of transport did Leonardo da Vinci design with a spring-powered mechanism?

Leonardo da Vinci designed a self-propelled cart with a spring-powered mechanism.

The cart, recorded in Leonardo’s notebooks around 1478 to 1480, used large coiled springs to store energy. Gears transferred that stored energy to the wheels, allowing the vehicle to move without an animal pulling it. A steering system and a mechanism for controlling the motion were also part of the concept.

The machine is often described as an early ancestor of the automobile, but it was not an engine-powered car in the modern sense. Its springs provided limited stored energy, and the surviving drawings leave some details open to interpretation.

In 2006, a working interpretation was built at the Museo della Scienza e della Tecnologia in Milan. That reconstruction helped demonstrate that the basic mechanism could operate.