Researcher launches open source accessibility toolbox

By Michael Brenneis and Chris McCahill
DOTs and planning agencies interested in measuring access to destinations have a growing number of packages and data sources to choose from. Folks not looking to reinvent the wheel are turning to shiny products like Citilabs’ Sugar Access, Conveyal, and Remix. But those with tighter budgets and a little more technical expertise can build on existing platforms like OpenTripPlanner, UrbanAccess, and now the Accessibility Toolbox for R and ArcGIS, featured recently in Transport Findings.

The toolbox, published on Github by Christopher Higgins at the Hong Kong Polytechnic University, is a convenient ArcGIS add-on available for both Pro and Desktop 10.X. It uses common data formats, including point or polygon feature classes, and ArcGIS’s Network Analyst.

The tool opens to a straightforward input window, letting users choose from a variety of accessibility metrics based on a hard cutoff or predefined impedance functions. Users with Python experience can also customize the impedance functions. Accessibility can be measured in terms of distance, travel time, or any other attribute in the network, using any geographically defined destination type.

SSTI ran the New York-based sample data provided with the tool, consisting of nearly 6,300 Census block groups and 175,000 pedestrian links derived from OpenStreetMaps. On a nicely tricked-out desktop PC, the tool produced results in about 90 minutes. There is an option for batch processing of larger projects. For agencies with the right data, skills, and computing power, the accessibility toolbox could be a useful addition.

Michael Brenneis is an Associate Researcher at SSTI. Chris McCahill is the Deputy Director at SSTI.