: These only happen when conditions are favorable—for instance, choosing to sit on a bench or stroll through a plaza. These activities are highly dependent on the quality of the public space.

: These are spontaneous interactions, like greeting a neighbor or watching street performers. They are "resultant" activities that flourish only when necessary and optional activities have good conditions. Designing for the Human Scale

Gehl's philosophy categorizes public activities into three distinct types, each influenced differently by the physical environment:

Modernist urban planning often prioritized cars and large-scale structures, leading to sterile environments. Gehl advocates for a return to the , emphasizing that the city should be designed for the speed of a pedestrian. Jan Gehl Using Public Space - LIFE BETWEEN BUILDINGS