Abstract
Commenting some of the participating papers it is pointed out: (1) that the accuracy that can be reached in a model is limited by the number of observed trips used in the calibration, and is often exaggerated; (2) that the distance function achieved after aggregation of two trip purposes is not a mean of the two original functions but normally falling slower than any of them, and (3) that the models must be based on variables and coefficients that can be forecast.