Environmental Justice Concentration Zones for Assessing Transportation Project Impacts

Abstract

Environmental justice (EJ) becomes a concern when minority or low-income communities (referred to as EJ populations) are disproportionately affected by transportation projects. The disproportionate impacts may relate to social, economic, or environmental burdens that EJ populations living in affected project areas will be forced to endure. An important component of any EJ assessment methodology is therefore the identification of EJ communities in a project area. The conventional approach classifies communities by means of threshold values into target and nontarget EJ populations. Research has demonstrated, however, that threshold values are largely influenced by the chosen community of comparison. In addition, the spatial distribution of target and non-target EJ populations within the affected area changed when the scale of geographic analysis changed. Because it has been argued that effective EJ analysis should consider all minority and low-income population groups regardless of their size, this research...