Re-conceptualizing accessibility to parks in multi-modal cities: A Variable-width Floating Catchment Area (VFCA) method

An increasing number of studies have sought to identify disparities or inequalities in the distribution of urban parks and green spaces. Results of these analyses have diverged considerably depending on the method used to assess accessibility. In this article, we revisit an increasingly popular technique, the two-step floating catchment area (2SFCA) method, and modify it to better align with the ways in which parks are planned and intended to be used. In this respect, we develop a Variable-width Floating Catchment Area (VFCA) method that models park attractiveness as a function of its size and number of amenities. We further compare accessibility according to four modes of transportation: bicycling, driving, public transit, and walking. A case study on access to public parks in Mecklenburg County, North Carolina, the U.S. is performed. In general, walking access to parks is found to be low throughout the county, access to larger regional parks is greatest for outlying suburban areas, and center city residents have access to a greater number of park amenities. Study results are compared to those obtained when using the original 2SFCA and indicate important differences in spatial accessibility patterns. Consequently, caution must be adopted when choosing a spatial access model and interpreting the resulting spatial patterns of accessibility. The parameters of the VFCA can easily be set to different values, making it a tool for scenario analyses. This study further improves our understanding regarding accessibility to public parks, which can help develop effective planning strategies.