Wednesday, June 8, 2016

Screening for Transportation Equity

This blog is written by Madeline Wander and Vanessa Carter from the USC Program for Environmental & Regional Equity (PERE).

Metro recently released its historic 2008-2015 Quality of Life Report that includes a novel focus on “disadvantaged communities.” Given the evidence that shows how low-income communities of color walk, bike, and use public transit the most—yet disproportionately suffer from public disinvestment in these modes—we are thrilled about this focus.

Of course to researchers like us, that begs the nerdy but important question: How should Metro define “disadvantaged communities?”

Creating indices are painstaking and not always satisfying work—compromises are always made along the way, and an index can only be as good as the underlying data. So, it’s really a miracle that we have any methods to start with and the Quality of Life Report uses two of them: CalEnviroScreen, developed by CalEPA’s Office of Environmental Health Hazards Assessment, and the Environmental Justice Screening Method, developed by academics at UC Berkeley, Occidental College, and USC (full disclosure: that last one includes us).

Metro’s 2008-2015 Quality of Life Report leans on the CalEnviroScreen (or, CES)—and for good reasons:

  • It is a scientifically-validated and widely-accepted mapping tool developed by the State to identify disadvantaged communities,
  • It combines many metrics to measure the cumulative impact of social vulnerability and environmental exposure at the neighborhood level, and
  • It is currently being used by the State to allocate millions of dollars of cap-and-trade revenue to benefit disadvantaged communities.

CES is a good tool. Full disclosure, again, we worked with State staff on their own methods as CES 2.0 was being developed. No index can do everything, but there are some ways in which CES can be strengthened that include:

  • Adding race/ethnicity as a variable: Despite the evidence that shows race is a more important factor than income in explaining residential proximity to environmental health hazards, CES excludes race/ethnicity as an indicator.¹ We know there are legal restrictions, here, but we’d be remiss not to point this out as it’s just so important.
  • Adding climate change vulnerability: CES doesn’t include any measure of this—such as level of tree canopy (which buffers climate change) or percent car ownership (which gives us an idea of mobility in the wake of a disaster). This is especially relevant since CES is being used to allocate climate change-related dollars.
  • Using regional scoring: CES uses statewide scoring, rather than regional scoring, meaning that it compares all of California’s Census tracts (proxies for neighborhoods) to each other and ranks accordingly. This is particularly concerning because California’s regions vary greatly, and comparing, for instance, neighborhoods in the Bay Area to those in the Central Valley to those in Los Angeles is like comparing apples to oranges.

This last feature is especially important for the purposes of assessing the quality of life in LA County as it can better tease out which communities are disadvantaged in the LA County context, which CES doesn’t necessarily do.² And we’d like to think that is why Metro included a comparison with the Environmental Justice Screening Method—which includes race, climate change vulnerability, and regional scoring—in its Quality of Life report.

But let’s back up a minute. While CES and the EJSM—and others like the California Health Disadvantage Index—provide a good starting point for identifying disadvantaged communities, none get at the specific question at hand: Which communities are disadvantaged when it comes to transportation?

If we are aiming to get transportation dollars to those communities who need it the most, we need to ask the right research question. And as gentrification leads to the displacement of disadvantaged communities across the region, we need a way to capture that dynamic process over the years.

This is all to say: We need a Transportation Equity Screening Method.

The good news is that we are part of a Transportation Equity Technical Work Group with Investing in Place, Metro, Advancement Project, SCOPE-LA, Public Health Alliance of Southern California, and the Los Angeles County Bicycle Coalition to start exploring these types of questions. So stay tuned in the coming months—as we will surely be calling on you all for words of wisdom!

¹See, for instance: Manuel Pastor, Rachel Morello-Frosch, and James Sadd, Still Toxic After All These Years: Air Quality and Environmental Justice in the San Francisco Bay Area (Santa Cruz, CA: Center for Justice, Tolerance and Community, University of California, Santa Cruz, 2007).

²See this website for more information on the EJSM: See this document for a detailed comparison of CalEnviroScreen and EJSM:


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