In his acclaimed book Life Between Buildings: Using Public Spaces, renowned Danish architect and urban designer Jan Gehl coins three categories of outdoor activities which we reference in our field guide. The first type he names are “Necessary activities.” These activities extend from people’s use of space via walking. Examples include everyday tasks, such as walking to work or school, getting the mail ,or walking a dog. Gehl claims that these activities would occur in every type of weather and yearlong as participants have no choice but to engage in this category of activities.
The second type of activities Gehl identifies is “optional activities,” which occur when there is a desire to participate in these activities and a time and a place favorable to participating in these activities. Examples include sitting outside or playing catch. Unlike necessary activities, optional activities are unlikely to occur in poor weather. Rather, optional activities occur when outside conditions and optimal, in particular if the weather is favorable. The frequency of optional activities is also dependent on the non-weather related environment. In dense urban settings of low quality optional activities exist at a minimum level. However, in a good physical environment, optional activities occur with high frequency.
“Social activities” are the third way in which people animate public space. Such activities emergence when people congregate in a place and socialize. These sort of activities include children playing, friends coming together to converse, and passersby briefly acknowledging each other. These activities are often spontaneous in nature and can occur in a wide variety of settings. Gehl says that these activities are “resultant” because they frequently evolve from activities in the other two categories as people in the same space meet, if only briefly. Similarly to optional activities, social activities are conditioned by the physical setting of the space. Gehl writes that in cities, social activities will be more superficial in nature as many interactions such as seeing and hearing others can be classified as social.