Measuring security in the built environment: Evaluating urban vulnerability in a human-scale urban form

Designing secured urban spaces is one of the main ambitions of urban planners during the planning and design process. People usually travel by foot through safe routes and urban spaces in the built environment as they are perceived as safe areas, such as: lighted paths, walking on the livable side of a sidewalk instead of walking beside a sealed facade, or away from unsecured building entrances. The way people use and interact in their built environment involves their cognitive perception, which depends upon the urban fabric details. Therefore, planners and decision makers aimed in understanding the way the components of the built environment affect unsecured environments so as to assess the risks before design decisions are made. However, they lack new approaches and models with which to evaluate a qualitative sense of security that is understandable on a human-scale in the built environment. This research deals with this gap in information and measures one unmeasurable qualitative aspect of the built environment, the sense of security, in quantitative terms based on a geo-spatial system, and then relate it to human-scale urban form. The Security Rating Index (SRI) establishes a GIS-based, quantifiable system to identify and rate insecure urban spaces to be used by urban planners and city decision makers to evaluate and improve urban resilience. The system is based on measurements of urban elements that influence the sense of security in the built environment, and can be used to identify characteristics and hot spots of unsecured spaces in a city. The SRI is demonstrated on several case studies on different scales.