Explanation Requested

Austin Metro buses have retractable bicycle racks on their front grilles, so that a bicycle rider can take his two–wheeled companion along with him on a bus ride. During the rather lengthy process of engaging the bicycle to the bus grille, those riders already inside the bus look on with expressions of, variously, inquisitiveness, boredom, patience.

Question: Correct me if I'm wrong -- as many of my readers know, I'm a little fuzzy on technology -- but if you have a bicycle don't you already have a means of transportation that can traverse a small city?

What possible reason, other than mechanical breakdown, could there be for choosing a slower, more expensive ride in the middle of a bike ride? You came to an uphill?