The wheel-based distance recorder associated with Leonardo da Vinci is an odometer. His design used a cart wheel connected to a counting mechanism so that repeated wheel rotations could be converted into a measurement of distance.
Leonardo’s version belongs to a long history of mechanical surveying instruments. A wheel of known circumference travels a predictable distance on each complete turn, allowing gears or falling markers to record the total. Such a device could assist with mapping, road measurement, and military engineering.
An odometer measures distance, not speed. A speedometer requires a time-based comparison, while a pedometer counts steps and a compass indicates direction. Leonardo’s design is also separate from his self-propelled cart: one records movement, while the other was intended to create it.