Despite its rapid acceleration into the world of automotive traffic jams and smog, Beijing has retained a strong connection to the bicycle, and its third wheel cousin the tricycle. Their presence is most felt in the narrow alleys of the hutong districts where cars have a difficult time maneuvering. Here in the alleys the bike remains a utilitarian object, used for hauling garbage, materials and people as well as establishing the means for countless mobile businesses. In Beijing, biking is not a leisure or sporting activity, it is foremost a work activity and a mean to an end. Given their emphasis on functionality over looks, many bikes have been modified or custom built to fit the unique demands of their owner.