A taximeter shall be equipped with a primary
indicating element.
Except when a taximeter is being cleared, the
primary indicating elements shall be susceptible to advancement only
by the rotation of the vehicle wheels or by the time mechanism.
Except when a taximeter is being cleared, indications
of fare and extras shall be visible at all times.
When a taximeter designed to calculate fares
upon the basis of a combination of mileage traveled and time elapsed
is operative with respect to fare indication, the fare-indicating
mechanism shall be actuated by the mileage mechanism whenever the
vehicle is in motion, at such a speed that the rate of mileage revenue
equals or exceeds the time rate, and may be actuated by the time mechanism
whenever the vehicle speed is less than this and when the vehicle
is not in motion. Means shall be provided for the vehicle operator
to render the time mechanism either operative with respect to the
fare-indicating mechanism.