Measuring performance: Accessibility metrics in metropolitan regions around the world

Automobile traffic backs-up as it travels north from San Diego to Los Angeles along Interstate Highway 5 in California December 10, 2013. REUTERS/Mike Blake (UNITED STATES - Tags: TRANSPORT SOCIETY) - RTX16CQU

Accessibility, or the ease of reaching valued destinations, is a key land use and transportation performance metric. While researchers have studied the concept for decades, its implementation in policy and practice is generally limited. The aim of this report is two-fold: first, to present how metropolitan areas currently incorporate accessibility into their transportation plans; and second, to examine how practitioners around the world have designed and implemented accessibility metrics. After reviewing 32 recent metropolitan transportation plans in North America, Europe, Australia, and Asia, plus surveying 343 different land use and transportation practitioners worldwide, the report finds: 

Most metropolitan transportation plans—22 of the 32 plans analyzed in this report—include accessibility in their vision, goals, or objectives, but many of these plans are not specific in their use of the term. Consequently, few plans include formal accessibility indicators to guide their decision-making processes. More often than not, accessibility is a buzzword with little tangible meaning.

Whereas about half (17) of the metropolitan transportation plans analyzed define “access-to destination” indicators, only eight of them use these indicators to comprehensively evaluate the benefits of land use and transportation projects. This step is, however, key to encourage the development of a more accessible built environment.

Among metropolitan transportation plans that use specific indicators, the plans tend to measure accessibility in a relatively uniform, narrow manner. Oftentimes, this means looking strictly at reaching all opportunities by either private vehicle or public transportation. This overlooks distinct accessibility levels among specific neighborhoods, for specific demographic groups, and walking or biking.

While nearly all practitioners surveyed for this report are familiar with the general concept of accessibility, only 55 percent use accessibility metrics in their work. These differences were consistent across all types of occupations and organizations. In turn, there is a considerable gap between the familiarity with the concept of accessibility and its practical implementation, including the use of particular types of metrics.

For practitioners who do not use accessibility metrics in their work, 52 percent express a lack of knowledge as a major barrier to implementation. Meanwhile, for practitioners who do use these metrics, 36 percent express that the use of such metrics is largely a result of their own initiative. As a result, many practitioners do not fully understand how to incorporate accessibility metrics into plans and other processes while facing certain technical barriers to adoption, including a lack of data.

Most practitioners agree that accessibility metrics can and should influence decision-making processes in their organizations or agencies, including 95 percent of practitioners who already use these metrics in their work. Although a lower share of practitioners who do not already use accessibility in their work agree with this sentiment, a majority still find that metrics can and should play an influential role in future decisions. Overall, this research illustrates the need to bridge the gap between accessibility research and practice. To support and successfully implement accessibility metrics into governing frameworks, it is essential to educate practitioners and follow best practices demonstrated in metropolitan areas that successfully implemented accessibility metrics into their formal governance frameworks. If the goal is to expand the adoption of accessibility planning and metrics, there is a demonstrated path forward.