1. A method for operating mass transportation systems wherein coordinates of position reference points (P 1 , P 2 , H 1 , H 2 , H 3 ) of desired stops of mass transit vehicles are monitored and data points (DPi) are determined with a spatial distribution around respective reference position points using at least one coordinate determination arrangement ( 14 , 15 ), said method comprising the steps of: a) grouping the data points (DPi) into a number of data point classes (C i ) in accordance with a first distance criterion around a desired reference position point; b) determining for each data point class (c i ) a center point (C′ i ); c) comparing a distance of each data point (DP i ) from the center-point of the data point classes (C i ) with a second distance criterion; and d) depending on the comparison: d1) selecting a data point as a starting point of an additional data point class (C x ); d2) re-grouping the data points Bpi into established data point classes (C 1 , C 2 ) and an additional data point class (C x ) in accordance with the first distance criterion, d3) repeating the steps b) to d2) until a predetermined termination criterion is fulfilled, and e) assigning the various data point classes to a respective reference point indicating a adjusted desired vehicle stop position.