Measuring Visual Access and Exposure Using Isovists Analysis to Explain Crime Hostpots in Residential Neighborhoods

• In Event: New Directions in Statistical Models to Study Neighborhood Crime

Abstract

Few research drew important links between visual attributes of the physical environment and crime such as above eye-level fences, overgrown shrubbery and other obstacles that can provide an offender with a potential location from which to see without being seen.

This study focuses on two relevant measures: visual access and visual exposure, where visual access is the degree to which one can monitor his or her spatial surroundings by sight, and visual exposure is the degree to which one may be monitored from other locations.

Using recently-developed space syntax based computer software, visual access is measured by isovist area and controllability, while visual exposure is measured by occlusivity and maximum isovist radial. Stranger to stranger crime data was collected at an address level on a 12 month period for three residential neighborhoods in Ypsilanti, Michigan. Visibility attributes are found to be important for criminals’ decision-making when they consider whether to offend at particular locations. Secondly, accessibility, visibility measures and the sociodemographics of residential environments should all be studied together in the analysis of crime. The author recognizes the importance of simulation tools made possible by Space Syntax in community policing and prediction of hot spots.

Author

• Linda Nubani, Michigan State University