Measuring Accessibility Spatial Equity using Average Space-Time Prisms

The space-time prism (STP) is the envelope of all possible travel paths in space and time between two anchor locations and times, measuring potential mobility or accessibility for individuals for a given travel and activity episode. Although the STP is a well-defined and widely applied measure of individual accessibility, there is no corresponding measure at the collective-level such as a neighborhood or community. A consistent collective-level measure would provide a benchmark for accessibility equity analysis. To fill this gap, this paper develops the concept of an average space-time prism (ASTP), the representative STP of a group of individual STPs with respect to size and shape. The ASTP provides the accessibility if an individual had the expected STP of the collective. This paper develops methods for calculating the ASTP for a set of individual STPs based on Fourier shape analysis techniques. It also shows how to use the individual and average STPs to conduct accessibility equity analysis. The authors illustrate their methods with a case study of measuring the impacts of new public transit service on healthcare access equity in a deprived neighborhood in Columbus, Ohio, USA.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ADD30 Standing Committee on Transportation and Land Development.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Lee, Jinhyung
    • Miller, Harvey J
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Maps; References; Tables;
  • Pagination: 21p

Subject/Index Terms

Filing Info

  • Accession Number: 01697946
  • Record Type: Publication
  • Report/Paper Numbers: 19-05109
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:42AM