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Research suggests mixed-income housing near rail hubs will boost equity and sustainability

Recent USC Price research found higher-income people reduce driving more than lower-income groups when living near rail transit.

By Eric Ruble

A recent USC Price study led by USC Price School of Public Policy Professor Marlon Boarnet, as featured by Transfers Magazine earlier this year, made a number of discoveries about the value of public transportation that you may not expect.

First, their findings suggest that city planners can both boost housing equity and reduce environmental impacts by encouraging residential development for all income levels near rail transit – not just affordable housing. But their most remarkable finding? Higher-income households reduce their driving more than low-income groups do when they live near rail transit.

Professor Marlon Boarnet (Photo: Thomas Queally)

It’s no surprise that California remains in the depths of a housing crisis. According to The New York Times, the median home price in the state is $800,000 – twice the national average – and more than 100,000 Californians sleep outside or in vehicles.

As the need for more affordable housing reaches new heights, there is a push to place homes in transit-oriented developments (TODs), partly to alleviate the additional financial burden of car ownership.

However, Boarnet and his colleagues found that Californians with higher incomesactually reduced their driving more when living near TODs compared to those with lower incomes. Therefore, the study claims high-income people “would contribute more to greenhouse gas reduction efforts than lower-income households via relocation to TOD.”

Boarnet, who is the Chair of the Department of Urban Planning at Spatial Analysis at Price, says this “key empirical takeaway” is largely that wealthier people drive more. If they opt to use rail transit instead, or take shorter driving trips that are typical near transit-oriented developments, it makes a marked difference.

Still, city planners and developers should not pounce on exclusively building luxury condominiums near public transit in the name of sustainability. Boarnet suggests a mix of housing types should be included in TODs.

“[Our research] highlights the importance of building more residential overall to catch up with demand in L.A. generally – both market-rate and affordable,” he said.

The data paints a nuanced picture for policymakers

Every seven to 10 years, the federal and state governments survey people to track their driving over a one-day period. The team analyzed these travel diaries to evaluate households both near and far from rail transit in the Los Angeles, San Francisco, San Diego and Sacramento areas. The data reinforced existing knowledge that regardless of income, people who live near rail transit hubs drive less.

As shown in the table below, the lowest-income residents drive a daily average of 17.7 miles when living within 0.5 miles of TOD, while those outside of that radius drove 32.7 miles. The wealthiest residents living near rail transit drive a daily average of 43.7 miles, while their counterparts beyond the 0.5-mile boundary drive 62.2 miles.

Boarnet says that while the difference is indeed larger for higher-income people, he believes boosting housing equity and reducing greenhouse gases are not mutually exclusive. With the right real estate development policies in place, the two objectives can be achieved simultaneously by simply increasing the amount of development across the income spectrum.

“Both those things, reducing driving and providing affordable housing, are really important goals,” he said. “We can greatly relax that tension by building just a whole lot more near rail transit, period.”

A collective effort aims to inform the future

Developers face more regulatory roadblocks in California than they do in many other states. Boarnet says in order to create cities that serve all residents in an environmentally sustainable way, the public and regulatory bodies should have access to a method that allows them to better understand transit and housing systems.

“It would be great if there was a nice decision-support tool,” Boarnet said.

Ultimately, Boarnet believes the conclusions provide state policymakers with reliable data they can use to promote building near rail stations, made stronger by the highly collaborative nature of the study.

Among those joining Boarnet was Raphael Bostic, the president and CEO of the Federal Reserve Bank of Atlanta and former chair of USC Price’s Department of Government, Management and Policy Process. PhD students also played a crucial role in bringing the project to fruition. The PhD student co-authors (all now graduated) were Seva Rodnyansky, Evgeny Burinskiy, Andrew Eisenlohr, Huê-Tâm Jamme, and Raul Santiago-Bartolomei.

In the end, there is no one solution that will work for all neighborhoods in all cities. But this research shows that by building diverse housing near rail transit, there is a path toward a future that is both more equitable for city dwellers and less environmentally damaging for everyone.