The Center for Transportation Studies at the University of Minnesota published Access Across America: Walking 2014, an online tool that visualizes the number of jobs accessible by walking across the country's 50 most populous metropolitan areas. 

While multiple definitions of accessibility exist, the number of destinations reachable within a given travel time by a certain travel mode is the most comprehensible and transparent, and the most comparable across cities and metropolitan areas. Walking 2014's rankings are determined by a weighted average of accessibility to jobs. Those reachable in ten minutes are weighted most heavily, with decreasing weights as travel time increases, up to 60 minutes. The study ranks the Chicago region fourth, after New York, San Francisco, and Los Angeles. 

The report presents detailed accessibility values for each metropolitan area, and block-level maps that illustrate spatial patterns of accessibility within each area.  This study is a companion to Access Across America: Transit 2014 report and a separate publication, Access Across America: Walking 2014 Methodology, describes in detail the data and methodology used in the walking study