Measuring temporal variation of location-based accessibility using space-time utility perspective

Abstract

Conventional location-based accessibility measures are static and cannot represent accessibility fluctuations at different times of day. To fill this gap, this study proposes location-based space-time accessibility measures to capture the temporal variation of location-based accessibility. Using the space-time utility perspective, the accessibility of a location is conceptualized as the space-time utility offered by a set of facilities accessible from the location. Individuals' facility choice behaviors among multiple alternatives are explicitly considered. A time-dependent facility attractiveness function is introduced to represent the temporal variation of individuals' needs to perform activities at a certain facility. The introduced function is formulated as two components: a time-invariant component representing individual satisfactions derived from activity participation at the facility, and a time-varying component expressing individuals' dynamic intensities to perform a certain type of activities at different times of day. To demonstrate the applicability of these proposed measures, a comprehensive case study has been carried out in Wuhan, China. The results of the case study show that the proposed measures can well capture the temporal variation of accessibility, due to the dynamics both of traffic conditions and of individuals' intensities in performing activities at different times of day. The proposed measures require moderate level of data, in terms of rich facility information; and most of these data could be extracted from social media applications.