Measuring urban job accessibility with distance decay, competition and diversity

As a key interface between urban transport and land use (workers and jobs) systems, job accessibility can provide a framework within which spatial and social interactions can be understood and interpreted. The extensive academic literature on job accessibility measurements suggests that there are many ways to represent, define, quantify, and interpret job accessibility. These measurements have been increasingly employed for exploring urban issues at varied spatial scales. However, in practice, an appropriate balance is required between the complexity of representation, accuracy of measurement and ease of interpretation and use. With this in mind, this paper demonstrates a modified measurement to represent, measure, and interpret, job accessibility and job opportunity, by incorporating the effects of competition, distance decay and job diversity. The measurement integrates a probabilistic methodology with a spatial interaction model. The methodology is implemented in a GIS environment and illustrated using the Amsterdam region of the Netherlands as a case study. We argue that this measurement can improve the application of job accessibility measurement for planning support practices.