Identifying Environmental Justice Communities for Transportation Analysis
Identifying Environmental Justice Communities for Transportation Analysis
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DOI：
10.1016/j.tra.2016.04.002
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
Dana Rowangould;A. Karner;J. London
中科院分区：
文献类型：
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作者：
Dana Rowangould;A. Karner;J. London
环境正义（EJ）是指旨在实现公平保护免受环境危害和获得跨人口群体利益的政策和宣传。研究表明，低收入社区和有色人种社区往往比普通民众面临更大的危害，从交通系统中获得的好处更少。然而，联邦政府授权的环境正义分析很少得出结论，认为项目可能会对这些社区造成不成比例的影响。本文探讨了用于定义EJ社区的方法，这是一个关键的分析步骤，其中很少有具体的指导，作为一个潜在的驱动力，在观察到的EJ结果的变化。本文以加州弗雷斯诺县的公交可达性为例，对比了三种识别EJ社区的方法：（1）常用的基于阈值的方法，该方法使用人口统计学对地理区域进行分组;（2）人口加权方法，该方法计算绩效指标的加权均值;（3）基于社区的EJ区域识别。分析表明，第一种方法是适当的针对交通投资，但不评估EJ的成果，而后两种方法是适当的评估EJ的成果。重要的是，用于定义EJ社区的方法可以极大地影响分析结果，可能会将不平等的发现从零转变为正，反之亦然。这些结果有重要的影响，交通规划机构和运输服务提供商进行EJ和公平分析，作为一个发现的不公平可能会导致设计的变化或缓解。
Environmental justice (EJ) refers to policy and advocacy intended to achieve equitable protection from environmental harms and access to benefits across demographic groups. Research has shown that low-income communities and communities of color are often exposed to greater harms and enjoy fewer benefits from transportation systems than the general population. However, federally-mandated EJ analyses rarely conclude that projects could result in disproportionate impacts to these communities. This paper investigates the methods used to define EJ communities—a key analytical step for which there is little specific guidance—as a potential driver of variation in observed EJ outcomes. Using a case study of transit accessibility in Fresno County, California, the paper contrasts three methods for the identification of EJ communities: (1) a commonly used threshold-based approach that groups geographic areas using demographics, (2) a population-weighted approach that calculates weighted means of performance measures, and (3) community-based identification of EJ areas. The analysis indicates that the first method is appropriate for targeting transportation investments but not for assessing EJ outcomes, while the second two methods are appropriate for assessing EJ outcomes. Importantly, the method used to define EJ communities can substantially affect the analytical outcome, potentially shifting a finding of inequity from null to positive or vice versa. These results have important implications for transportation planning agencies and transportation service providers that conduct EJ and equity analyses, as a finding of inequity may lead to design changes or mitigations.