The passage of Senate Bill 375 in 2008 ushered in a new era of regional sustainability planning in California. Now, regions must coordinate their transportation planning and investment with land use strategies that will help to reduce greenhouse gas emissions. But what if the hundreds of new fixed-rail stations recently built or planned for California’s major metros, along with related “transit-oriented development,” inadvertently displace new households, leading to more driving and thus more emissions? That’s what the California Air Resources Board asked our team to figure out.
In theory, there are at least two different ways transit investment could displace households and lead to more driving: displacement and exclusion. By making neighborhoods more accessible, transit could attract new residents, businesses, and/or development, and thus raise land values and rents, in a pattern of gentrification. Lacking an ownership stake, locals may be displaced, with more affluent households moving in. Even though they may be attracted to the neighborhood because of the availability of transit, these households are more likely to own cars. Meanwhile, low-income households may now be displaced or excluded from moving into the neighborhood, able to find affordable housing only in more remote neighborhoods far from transit. If they drive more than before, and if new higher-income households do not reduce their driving when moving near rail, then the region as a whole could see more vehicle miles traveled (VMT).
Our research confirms that rail transit investment in the San Francisco Bay Area and Los Angeles County is related to gentrification and displacement – but not always, and not in readily predictable ways. Contextual factors shape outcomes: downtown areas are more likely to gentrify than suburban neighborhoods, and more established transit station areas see more gentrification as well. Even when transit neighborhoods gentrify, they may not displace residents. Displacement may occur before gentrification, decades afterward, or not at all, depending, at least in part, on the protections in place for tenants and the amount of subsidized housing built in the neighborhood.
Transit stop in the Castro, San Francisco.
Transit neighborhoods tend to experience demographic shifts; in Los Angeles, that often means new higher-income residents, usually non-Hispanic Whites, while in the Bay Area, transit also attracts new residents with higher levels of educational attainment. Neighborhoods with concentrations of minorities are more likely to gentrify, but effects differ between regions and in different decades.
Although this study did not explicitly examine the role of market-rate housing in displacement, we do find that gentrification in Los Angeles and the Bay Area transit neighborhoods cannot generally be attributed to new development, as both areas experienced relatively little residential development during the period of observation. Future research should examine in more detail the relationship between new market-rate development and the displacement of neighborhood residents.
Do transit neighborhoods change driving patterns? While low-income households do have lower VMT than high-income households, it turns out that high-income households have a greater reduction in VMT associated with rail transit. But this does not mean displacement of low-income households by high-income households would necessarily decrease VMT. Development near rail transit is only likely to succeed at reducing VMT in the entire region if it is accompanied by an increase in density in the neighborhood. In other words, transit alone cannot help us meet our greenhouse gas reduction goals unless we ensure that more people live nearby.
Light rail stop in Los Angeles.
Just as patterns of gentrification and displacement vary by context, so do the effectiveness of policy solutions. Little is yet known about which tools work best in different types of transit neighborhoods, and it is likely that cities and regions will need to adopt multiple approaches, including both housing preservation and production, as well as tenant protections. Yet, this study suggests the need to become more aware of the potential for displacement with transit investment and to act proactively to ensure that the population grows while the housing remains affordable.