An odometer in a car measures:

In kinematics, distance is the total path length a body covers regardless of direction; speed is the rate at which that distance changes with time (distance ÷ time); and acceleration is the rate at which velocity itself changes with time. These are three distinct physical quantities, with different units and different measurement requirements.

An odometer accumulates the total path length the car has covered: as the wheels turn, it keeps adding up the distance corresponding to each rotation, building a running total that only grows larger as the car moves further. What the odometer displays is exactly that accumulated running total — the distance travelled by the car — not a per-time rate.

Checking the other three quantities against this reading confirms it:

• instantaneous speed of the car — a rate at one specific moment (km/h) that rises and falls from instant to instant; the odometer's display is a cumulative count that keeps growing, not a per-moment rate.

• average speed of the car — total distance divided by the total elapsed time for a journey, a single rate value; the odometer's display is simply the distance part as an ever-increasing count, never divided by time to give a rate.

• acceleration of the car — the rate at which velocity itself changes over time; the odometer's display remains a plain cumulative distance count, unrelated to how the car's velocity is changing.

Hence, the odometer's reading corresponds to the distance travelled by the car.