The Impact of Analysis Boundaries in Accessibility Evaluations: A Case Study

Recent working paper:

• Palmateer, Chelsey, Owen, Andrew, and Levinson, D. (2016) The Impact of Analysis Boundaries in Accessibility Evaluations: A Case Study (Working Paper).

  

A case study transit project, the Harris County Transit Re-Imagined Bus Network, is utilized to evaluate the impact of analysis boundaries on accessibility analysis. Results from the case study indicate that choice of analysis boundaries can have a significant impact on the value of absolute accessibility measures. In general the trend shows that the tighter the analysis boundary is to the network, the higher the value of the absolute accessibility measure. However, relative accessibility measures such as percent difference between scenarios are consistent regardless of analysis boundary size. This indicates that the choice of analysis boundary is of only moderate importance for scenario comparisons within the same analysis boundary. However, when comparing between different regions or in areas within different boundaries, the choice of those analysis boundaries could have a significant impact on all results. Furthermore, care should be taken to indicate the analysis boundary used whenever an absolute accessibility measure is presented.