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8.0 Statistical processing of passenger numbers

Since no automatic passenger counting system works error-free, in most cases the number of passengers boarding does not match the number of passengers alighting.  Therefore, the raw data (the numbers of passengers boarding and alighting that have not been processed) acquired by the passenger counting system undergo subsequent statistical processing, in which the data are checked regarding plausibility and slight corrections are made.

The most probable case occurring in practice is assumed for the plausibility check and for the corrections.  Statistical processing produces figures with a lower balanced error for boarding passengers and alighting passengers compared to the raw data.

Statistical processing is based upon the following assumptions:

• At the first stop of a line, there are only persons boarding, but no alighting.
• At the last stop of a line, there are only persons alighting, but no boarding.
• At the last stop of a line, all passengers exit (at the last stop, the number of persons in the bus is zero).
• The number of passengers of a line corresponds to the mean value of counted persons boarding and alighting.
• The missing or the excess passengers boarding or alighting are distributed onto the individual stops. Doing so, stops where a larger number of passengers has entered or exited are corrected stronger than stops, where a smaller number of passengers has entered or exited.
• Distribution of missing or excess passengers boarding or alighting to the individual stops takes place under the condition that there are no negative figures of persons within the vehicle.

INVETEL Ltd will perform statistical processing, however it is considered to be out of the scope of our standard supply arrangements, therefore it would be considered separately to the supply of APC.