Policy makers, urban planners, architects, sociologists, and economists are interested in creating urban areas that are both lively and safe. But are the safety and liveliness of neighborhoods independent characteristics? Or are they just two sides of the same coin? In a world where people avoid unsafe looking places, neighborhoods that look unsafe will be less lively, and will fail to harness the natural surveillance of human activity. But in a world where the preference for safe looking neighborhoods is small, the connection between the perception of safety and liveliness will be either weak or nonexistent. In this paper we explore the connection between the levels of activity and the perception of safety of neighborhoods in two major Italian cities by combining mobile phone data (as a proxy for activity or liveliness) with scores of perceived safety estimated using a Convolutional Neural Network trained on a dataset of Google Street View images scored using a crowdsourced visual perception survey. We find that: (i) safer looking neighborhoods are more active than what is expected from their population density, employee density, and distance to the city centre; and (ii) that the correlation between appearance of safety and activity is positive, strong, and significant, for females and people over 50, but negative for people under 30, suggesting that the behavioral impact of perception depends on the demographic of the population. Finally, we use occlusion techniques to identify the urban features that contribute to the appearance of safety, finding that greenery and street facing windows contribute to a positive appearance of safety (in agreement with Oscar Newman's defensible space theory). These results suggest that urban appearance modulates levels of human activity and, consequently, a neighborhood's rate of natural surveillance.
@cite_31: It is hypothesized that collective efficacy, defined as social cohesion among neighbors combined with their willingness to intervene on behalf of the common good, is linked to reduced violence. This hypothesis was tested on a 1995 survey of 8782 residents of 343 neighborhoods in Chicago, Illinois. Multilevel analyses showed that a measure of collective efficacy yields a high between-neighborhood reliability and is negatively associated with variations in violence, when individual-level characteristics, measurement error, and prior violence are controlled. Associations of concentrated disadvantage and residential instability with violence are largely mediated by collective efficacy.
@cite_16: This article reveals the grounds on which individuals form perceptions of disorder. Integrating ideas about implicit bias and statistical discrimination with a theoretical framework on neighborhood racial stigma, our empirical test brings together personal interviews, census data, police records, and systematic social observations situated within some 500 block groups in Chicago. Observed disorder predicts perceived disorder, but racial and economic context matter more. As the concentration of minority groups and poverty increases, residents of all races perceive heightened disorder even after we account for an extensive array of personal characteristics and independently observed neighborhood conditions. Seeing disorder appears to be imbued with social meanings that go well beyond what essentialist theories imply, generating self-reinforcing processes that may help account for the perpetuation of urban racial inequality.
@cite_8: Fear of crime is a serious problem on university and college campuses. Although fear has many causes, one potential source of fear may arise from the design of the physical environment. In areas having a climate of fear (from incivilities or other factors), proximate cues in the surroundings may affect feelings of safety. In theory, concealment, blocked prospect into the concealment, and blocked escape contribute to fear. Following one study that tested this theory in a highly atypical building, the present study extended the test to a more typical campus outdoor space. Fear-maps elicited from students were compared with physical indices of concealment, blocked prospect, and escape. As predicted by the model, fear related to the presence of trees, shrubs and walls which provided concealment, limited prospect and blocked escape. The results highlight the importance of the role of uncertainty in environmental response and suggest that reductions in fear and opportunities for crime on campus may be achieved through changes in the character of campus outdoor spaces.
Moreover, the BWT has been criticized by work showing that the social and ethnic context of a neighborhood may matter more than urban disorder. In Sampson @cite_31 and Sampson and Raudenbush @cite_8 @cite_16 , community data from Chicago was used to argue that racial and economic context were more predictive of disorderly behavior than physical disorder. To help bridge their results with the literature, Sampson and Raudenbush @cite_8 proposed an alternative interpretation of the theory, where both neighborhood disorder and crime, are manifestations of a lack of informal forms of control within disengaged and distrusting communities. The reframed theory, therefore, interprets the link between disorder and crime as a manifestation of the lack of informal forms of social control and organization.