Heern: I object to the mayor' s proposal that taxicabs pick up and drop off passengers only at designated stops. This proposal aims to reduce traffic jams and accidents, but if the mayor herself were affected by such a law, she would oppose it. Thus the proposal is without merit. The reasoning in Heern's argument is most vulnerable to criticism on the grounds that this argument ['takes for granted that the frequency and location of designated stops would inconvenience most taxicab users', "takes for granted that other people would share the mayor's dissatisfaction with the proposed law", 'presumes, without providing justification, that the proposed law would not be the most effective way to reduce traffic jams and accidents', "focuses on the mayor's preferences instead of addressing the merits of the proposal"]