Does green transportation promote accessibility for equity in medium-size U.S. cites?

The link between accessibility and social equity attracts much attention for promoting sustainability. However, there is no comprehensive approach to elevate the role of accessibility in evaluating transportation system over social equity by considering the variety of urban opportunities and population groups from green transportation perspective. Our goal is to develop such a framework to evaluate transportation equity by focusing on accessibility via transit and cycling. Applying the framework to Fresno, California, and Cincinnati, Ohio with different development patterns, we delineate service areas at block-group level with five time-thresholds. The service area is used to count the number of urban opportunities: jobs, dining, churches, libraries, parks, multi-use paths, schools. We then use statistical comparison and geographical mapping to identify accessibility gap to these opportunities between advantaged and disadvantaged groups defined by income, property value, education, vehicle ownership, race, and age. The results indicate the extent of differences in accessibility is sensitive to threshold specification of grouping population. The findings suggest that the efficiency of transit service needs to be improved to reach the same level of cycling, while they do help with the accessibility for economically disadvantaged neighborhoods. Considering school enrollment, the accessibility to opportunities in Fresno performs differently while students in Cincinnati benefit from good accessibility to most resources. The results of accessibility to multi-use paths highlight the need of providing more efficient green transportation facilities for less wealthy neighborhoods. Variation in accessibility between groups underscores the importance of developing policies to meet the needs of diverse social groups.