From TIGER to Audit Instruments: Measuring Neighborhood Walkability with Street Data Based on Geographic Information Systems

Abstract

The relationship between urban form and pedestrian mobility is an area of increasing policy interest within the planning, transportation, environmental, and public health fields. Many municipalities are seeking to adopt variations of smart growth principles that seek, in part, to increase pedestrian choice in an urban environment. This paper explores how the path network around key urban destinations can be visually and quantitatively analyzed to provide useful planning and evaluation tools for these pedestrian-oriented environments. Neighborhood environments surrounding transit stops and schools are used as examples of how to visualize and quantify local walkable environments. Three key techniques based on geographic information system (GIS) are presented: street network classification, pedestrian catchment areas, and intersection intensities. Although such measures have been used elsewhere to some extent, this paper includes the idea of impedance, a method to help distinguish between automobile-oriented and pedestrian-oriented areas. A series of GIS-based qualitative visualization and quantitative analyses are presented, as are some basic steps on conducting the analyses within a GIS environment. A discussion of key data sources, including TIGER (topologically integrated geographic encoding and referencing) street data and new pedestrian audit instruments, are also presented as different ways to assess local walkability.