Comparing Circular and Network Buffers to Examine the Influence of Land Use on Walking for Leisure and Errands

Background: There is increasing interest in examining the influence of the built environment onphysical activity. High-resolution data in a geographic information system is increasingly being usedto measure salient aspects of the built environment and studies often use circular or road networkbuffers to measure land use around an individual's home address. However, little research hasexamined the extent to which the selection of circular or road network buffers influences theresults of analysis.The objective of this study is to examine the influence of land use type (residential, commercial,recreational and park land and institutional land) on 'walking for leisure' and 'walking for errands'using 1 km circular and line-based road network buffers. Data on individual walking patterns isobtained from a survey of 1311 respondents in greater Vancouver and respondent's postal codecentroids were used to construct the individual buffers. Logistic regression was used for statisticalanalysis.Results: Using line-based road network buffers, increasing proportion of institutional landsignificantly reduced the odds of 'walking for leisure 15 minutes or less per day' no significant resultswere found for circular buffers. A greater proportion of residential land significantly increased theodds of 'walking for errands less than 1 hour per week' for line-based road network buffer whileno significant results for circular buffers. An increased proportion of commercial land significantlydecreased the odds of 'walking for errands less than 1 hour per week' for both circular and linebasedroad network buffers.Conclusion: The selection of network or circular buffers has a considerable influence on theresults of analysis. Land use characteristics generally show greater associations with walking usingline-based road network buffers than circular buffers. These results show that researchers need tocarefully consider the most appropriate buffer with which to calculate land use characteristics.