Drawing on longstanding issues of equitable access to public transit in her district, U.S. Rep Ayanna Pressley of Massachusetts joined federal lawmakers on Thursday to launch a new caucus designed to tackle obstacles to reliable public transportation facing less prosperous communities around the country.

In her speech, Pressley focused on neighborhoods in her home district, particularly along the MBTA’s Fairmount Commuter Rail Line, including Mattapan, Roxbury and Dorchester.

“For years, transportation systems in (Massachusetts’ 7th district) and across the country have perpetuated disparities, forcing many of our low-income neighbors to pay more, endure longer commutes and lose pay and family time,” Pressley said Thursday morning. “Access to safe, reliable and inclusive modes of transportation is a matter of social justice.”

Pressley said residents in her district who endure the longest commute times also live in the poorest neighborhoods.

“In fact, black bus riders in the Boston metro area spent 66 more hours per year waiting, riding and transferring buses than white bus riders,” she said. “These disparities disrupt economic mobility and create unnecessary barriers to success.”

Launched on Thursday, the Future of Transportation Caucus will look at issues of equity, access and sustainability across the nation’s transportation system.

In recent weeks, Boston Mayor Martin Walsh also emphasized the importance of connecting residents to transit in economically disadvantaged suburban areas — and in particular, along the Fairmount Line.

“All you have to do is look at a map of the system and you can see the areas of Boston with no subway service,” Walsh said previously. “It’s the Fairmount Line that’s a game changer.”