Space-time measures of demand for service: Bridging location modelling and accessibility studies through a time-geographic framework

Fang Ren, Daoqin Tong, Mei Po Kwan

Research output: Contribution to journalArticle

8 Scopus citations


Demand for service in location modelling is often evaluated based on the spatial proximity of fixed and static reference locations of demand (e.g. home) to a facility, which ignores person-specific activity-travel patterns and the temporal changes in demand for service throughout the day. To address these limitations, this study draws upon recent developments in space-time measures of individual accessibility to explore the spatial and temporal structures of demand by considering individuals' space-time constraints and impact of existing urban structures. Based on a time-geographic framework, eight space-time demand measures were developed and compared with three conventional location-based demand measures for 12 hospitals through an empirical study conducted in Columbus, Ohio. The results show that geographic proximity between clients' home and facilities may not be an effective indicator for service demand, and conventional demand measures tend to underestimate potential demand for service in most situations. The study concludes that space-time demand measures that take into account people's activity-travel patterns in space-time would lead to better estimation of demand for service in most cases.

Original languageEnglish (US)
Pages (from-to)329-344
Number of pages16
JournalGeografiska Annaler, Series B: Human Geography
Issue number4
StatePublished - Dec 1 2014



  • Demand for service
  • Space-time constraints
  • Space-time measures
  • Time geography

ASJC Scopus subject areas

  • Geography, Planning and Development

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