Through discussions with the client and other additional research, it was determined that safety should be the most important factor in the playability analysis. Regardless of the score achieved through a combination of the other factors, if a play space was not located in a safe neighbourhood it should not score well on overall playability. The general safety index was developed through a combination of crime density, graffiti density, and street lighting density in a MCE. While safety has been included in studies of pediatric walkability, it was determined that as the most important factor in determining playability, it should be included as a separate factor. The interactive map that is included below identifies the safety level throughout the City of Vancouver.
A measure of crime density was achieved using 2010 crime data from the City of Vancouver. As this study included information from the 2011 Census, the 2010 crime statistics were used because of their close temporal relationship. The crime statistics are a record of all thefts from automobiles, thefts of automobiles, commercial break and enters, and criminal mischief in the city. Over 15,000 crimes were geolocated in order to create a crime shapefile. These points were then used to create a point density layer, revealing which parts of the city had the highest density of crime. This layer was then converted into a raster for use in the MCE. Click to view the crime map
Studies have shown that the physical appearance of a neighbourhood plays a significant role in the perceived level of safety. While the physical appearance of all of the neighbourhoods in the city could not be observed in the time allotted for this study, graffiti could be used as an indicator of the appearance of that neighbourhood. The City of Vancouver updates their graffiti shapefile on a weekly basis, so the current shapefile was considered an accurate representation of the neighbourhood’s current appearance. This shapefile was used to create a point density layer indicating the areas of the city with the highest density of graffiti. Click here to view the graffiti map
The City of Vancouver publishes the location of all lamp posts within the city, and these points were used to generate an overall light density shapefile. The higher the level of light the more visible one is, and the safer they may feel. The point density file allowed for the determination of how much light is located with a given square kilometer. This shapefile was converted into a raster and included in the safety MCE. Click here to view the lighting map
Each of these described data layers were organized in IDRISI upon completion to calculate the overall safety index using the IDRISI Decision Wizard. The values of each raster data layer were converted into fuzzy sets, providing a standardized range of values on a scale of 0-255. Each factor was given equal weight in the analysis. The final output of the safety MCE process is a raster map of the study area visualizing the degree of safety at the DA scale (interactive map above). The resultant raster was then used as a variable for the final playability MCE.