Accessibility in practice: A new guide from SSTI

By Chris McCahill

The Virginia Office of Intermodal Planning and Investment recently released its new report, Accessibility in practice: A guide for transportation and land use decision making, developed by SSTI with several partners. The guide describes ways of measuring accessibility and, more importantly, how to use those metrics in planning, project evaluation, and other transportation and land use decisions. The information is useful for any state or local agency interested or already involved in making these kinds of decisions.

Accessibility metrics describe people’s ability to reach destinations by different modes, at different times of day, and under various conditions. Accessibility is a critical measure of transportation system performance but, until recently, has only been a vague planning concept or a metric used mainly by researchers and academics. New data, tools, and accepted practices are beginning to change that.

Virginia has led the nation in state-level accessibility analysis since its Smart Scale project prioritization law passed in 2014. In that time, VDOT has scored nearly 700 projects and made the commercial accessibility software, Sugar Access, available statewide for local planners and transportation agencies. This new guide grew out of that commitment.

The guide outlines general concepts, data needs and availability, analysis tools, and other considerations in measuring accessibility. It describes different ways accessibility can be measured—e.g., access to jobs, access to non-work destinations, statewide, and project-level—and demonstrates how the metrics can be used in several specific project evaluation examples. It also briefly describes the potential use of accessibility metrics in predicting outcomes such as travel demand and transit ridership.

This guide is available for download in SSTI resources.

Chris McCahill is an Associate Researcher at SSTI.