Access Across America: Transit 2014 Methodology

Accessibility is the ease of reaching valued destinations. It can be measured for various transportation modes, to different types of destinations, and at different times of day. There are a variety of ways to define accessibility, but the number of destinations reachable within a given travel time is the most comprehensible and transparent, as well as the most directly comparable across cities. This report describes the data and methodology used in the separate publication, Access Across America: Transit 2014. That report examines accessibility to jobs by transit in 46 of the 50 largest (by population) metropolitan areas in the United States. Transit is used for an estimated 5 percent of commuting trips in the United States, making it the second most widely used commute mode after driving. Rankings are determined by a weighted average of accessibility, giving a higher weight to closer jobs. Jobs reachable within ten minutes are weighted most heavily, and jobs are given decreasing weight as travel time increases up to 60 minutes.