Extending public transportation to a metropolitan neighborhood for the first time can, in some cases, raise rents, bringing in a population of wealthier residents who would rather drive than take public transportation.

That’s the conclusion of a report by the Kitty and Michael Dukakis Center for Urban and Regional Policy, which found that new public transit investments can sometimes lead to gentrification that prices out renters and low-income households—people considered core public-transportation users—working against the public goal of boosting transit ridership.

The study, released today, urged planners and policymakers to consider the unintended consequences of neighborhood gentrification when expanding or improving public transit, given the risk that transit investment can cause undesirable neighborhood change.

“Transit planners frequently speak of the need for transit-oriented development to support ridership, but what transit stations need is transit-oriented neighbors who will regularly use the system,” said Stephanie Pollack, the report’s lead author and associate director of the Dukakis Center.

“In the neighborhoods (around the country) where new light rail stations were built, almost every aspect of neighborhood change was magnified,” added Barry Bluestone, director of the Dukakis Center and the report’s coauthor. “Rents rose faster; owner-occupied units became more prevalent. Before transit was built, these neighborhoods had been dominated by low-income, renter households.”

The report, “Maintaining Diversity In America’s Transit-Rich Neighborhoods: Tools for Equitable Neighborhood Change,” was funded by the Rockefeller Foundation. It includes new research analyzing socioeconomic changes in 42 neighborhoods in 12 metropolitan areas across the United States first served by rail transit between 1990 and 2000.

The report’s findings, researchers said, also raise concerns about equity. Core transit riders are predominantly people of color and/or low-income who disproportionately live in transit-rich neighborhoods. Researchers calculated that transit-served metropolitan regions are currently home to over half of all African Americans, 60 percent of all Hispanics and 70 percent of all immigrants in the United States.

The report’s recommendations include advising policymakers to get ahead of the issues using coordinated and community-responsive planning tools, and designing policies that attract core and potential transit users to these now transit-rich neighborhoods. To moderate increases in rents, future housing policies should include funding for land and property acquisition, preservation of existing affordable housing, and creation of new affordable housing, researchers said.

In conjunction with the release of the report, the Dukakis Center launched a web-based Policy Toolkit for Equitable Transit-Rich Neighborhoods, available at http://www.dukakiscenter.org/TRNEquity.