Principal Investigator
Brian Lee, Department of Landscape Architecture

Undergraduate Researcher
Jared A. Cunningham, Department of Landscape Architecture

Project Summary
Walkability and Bikability Assessment and Least Cost Improvement Methodology

Project Description
The Centers for Disease Control and Prevention and the Dietary Guidelines for Americans 2005 recommend that children and adolescents frequently participate in at least 60 minutes of moderate-intensity physical activity, preferably on a daily basis. One way to increase physical activity is to incorporate it into the child's daily school commute. However, neighborhoods have often been designed with the automobile exclusively in mind. Consequently, children walking or bicycling to school is not always a safe alternative to the car or school bus. With ArcGIS and the Spatial Analyst extension, students identified dangerous walking and bicycling areas, proposed design safety solutions, and evaluated alternatives for improving adverse conditions.

The study area covered approximately .60 square miles and contained neighborhoods built from the early 1900s through the 1960s. The destination within the study area was an elementary school located near the center. The student team began by developing a neighborhood audit for streets and intersections that used the Likert Scale rating system. A Likert Scale is a qualitative rating system that is often used to measure judgments. Ratings are indicated along a continuum, in this case on a scale of 1 through 5, indicating the quality of the street or intersection in terms of safety or ease of movement.

Basemaps were prepared from publicly available geospatial data from the Kentucky Geography Network to aid in field data collection and subsequent analyses, and the ordinally scaled qualitative audit data was entered into ArcGIS as attributes for a shapefile. The shapefile was used for initial audit visualization and analysis. Using the audit data, the team was able to produce a series of maps depicting current walking and bicycling conditions within the project area and another series of maps that included straight-line walking distance, topographic slope, and children density.

The initial audit analyses and ancillary data helped visualize where problems existed and allowed the team to debate strategies on how to improve the walkability and bikeability for the neighborhood school. To determine the relative costs of going to and from school for the children, the team used the Cost Distance tool of the Spatial Analyst toolbox in ArcView 9.1 with the ArcGIS Spatial Analyst extension.

The team evaluated three strategies to improve conditions based on a combination of the slope, audit, and children density. The final analyses evaluated three solutions indicating a 12 percent, 48 percent, and 50 percent increase in overall study area walkability and bikeability. Because 50 percent of the evaluation was based on land slope, none of the three proposals for existing neighborhoods improved walkability and bikeability 100 percent. The student team was able to propose strategies that included a range of on-the-ground changes. Potential changes included adding proper curb cuts, painting crosswalks, adding stop signs, modifying vegetation, and adding sidewalks. These modifications ranged in cost and difficulty of implementation. The students also evaluated not only the types of strategies but also where to implement them.

This analysis and proposal evaluation method allowed for more informed debate among the team members on the best ways to improve walkability/bikeability conditions. Simply by changing the cost friction surface and rerunning the Cost Distance tool, the students could quickly test a variety of design solutions. Although not specifically part of this academic exercise, a cost-benefit analysis could be included for additional help in making decisions. This method could be easily adopted for use in projects underway or planned by government and nonprofit organizations as well as the private sector.

Related Links

• Environmental Systems Research Institute (ESRI)

• ESRI ArcUser Magazine Article: Why Not Walk to School Today?

• ESRI ArcGIS: A Complete Integrated System

• ESRI ArcGIS Spatial Analyst: Advanced Raster GIS Spatial Analysis