The fastest way to reach your destination in a crowded city is usually public transportation, especially when traveling between boroughs or neighborhoods. It may smell and a few people may breathe or sneeze on you, but at least you won't have to worry about traffic jams.
Celebrities can't resist the convenience of the bus or subway, and despite the luxury of a private car, the rich and famous often hitch a ride on mass transit.
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It's a refreshing turn to see celebrities commute with the common people — and even give up their seat. It looks like they're human after all.