Streets, being vital elements of public spaces, provide mobility and social contact. Beyond their transportation character, streets are the locations where people may interact with each other, satisfy their needs, and express themselves. These functions contribute to the liveliness of streets and have a significant influence on social life in public spaces. This research examines street characteristics as factors of liveliness that help us to identify the street as a public space. Taking physical features, visual identity, functions, and activities as parameters of street character; the research examines Istanbuls Bagdat Avenue by emphasizing these parameters on the liveliest sections of the avenue. The two-stage organized research outputs have shown that the liveliest sections of the avenue include variety of businesses, individual retailers, segments with a unique identity, and buildings with permeable and articulated facades. It can be asserted that the streets characteristics encourage individuals to behave in a way that enhances publicity and that the streets characteristics help in creating a more attractive place and a lively atmosphere for people to behave in a comfortable way that strengthens the publicity. This research aims to contribute to academic literature to develop a framework for rethinking design and planning for revitalizing urban life and explaining the human aspect of environmental design.