OIML Recommendation R 21:1975

Taximeters

Scope: This Recommendation concerns time and distance counters known as "taximeters" for fitting on public hire vehicles. "Taximeters" are measuring instruments which totalize continuously and indicate at any moment of the journey the sum payable by the user of a public vehicle as a function of the distance travelled and – below a certain speed – of the length of time occupied, independently of supplements authorized by the regulations in force.