Geographical Analysis (1998) 30(3): 191-216.
Space-time and Integral Measures of Individual Accessibility:
A Comparative Analysis Using a Point-based Framework
Mei-Po Kwan
Abstract: Conventional integral measures of accessibility,
although valuable as indicators of place
accessibility, have several limitations when used to evaluate individual accessibility. Two
alternatives for overcoming some of the difficulties involved are explored in this study.
One is to adapt these measures for evaluating individual accessibility using a
disaggregate, non-zonal approach. The other is to develop different types of measures
based on alternative conceptual framework. To pursue the former alternative, this study
specifies and examines 18 gravity-type and cumulative-opportunity accessibility
measures using a point-based spatial framework. For the latter option, 12 space-time
accessibility measures are developed based on the construct of feasible opportunity set.
This paper compares the relationships and spatial patterns of these 30 measures using
network-based GIS procedures. These indices are computed using travel diary data
collected in Columbus, Ohio, and a digital data set of 10,727 selected land parcels.
Results of this study indicate that integral and space-time indices are distinctive types of
accessibility measures whose patterns are determined by different factors. Due to the
contextual and situational nature of individual accessibility, measures based on the space-
time framework offer attractive alternatives for capturing the effect of personal attributes
complex travel behavior and space-time constraints on personal accessibility.
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