Low-income households in the U.S. suffer from disproportionate exposure to air pollution from transportation sources, such as trucks, trains, and planes. Low-income households also use transit more frequently than affluent households do; however, they still rely heavily on vehicles to fill their mobility needs. Due in part to the high cost of housing near job and transit centers, many low- and moderate-income individuals are stuck with long commutes in vehicles that are older, less efficient, and costlier to maintain than the average privately owned vehicle. This is especially true in high-housing-cost states like California.

California is also at the forefront of progressive environmental initiatives, including many innovative transportation-related environmental justice programs. The following research from the Luskin Center for Innovation (LCI) has informed the design and implementation of transportation equity programs in California.