Anthony Roberts set out to walk to a convenience store on the opposite side of a busy highway in Kansas City, Mo., one afternoon. It wasn’t an easy trip.

First, he had to detour out of his way to reach an intersection. Then he had to wait for the light to change. When the walk signal finally came on, he had little time to cross several lanes of traffic and reach the highway’s wide median. Finally, he had to make it across the other set of lanes to complete his trek.

“For a person who doesn’t have a car, it’s very hard, especially in the wintertime,” Mr. Roberts said. “No one wants to take a risk with their lives trying to cross the highway.”

Mr. Roberts’s journey is a small example of the lasting consequences stemming from the construction of highways slicing through urban neighborhoods in cities around the country. Completed in 2001 after being in the works for decades, the highway in Kansas City, U.S. 71, displaced thousands of residents and cut off predominantly Black neighborhoods from grocery stores, health care and jobs.

Kansas City officials are now looking to repair some of the damage caused by the highway and reconnect the neighborhoods that surround it. To date, the city has received $5 million in funding from the Biden administration to help develop plans for potential changes, such as building overpasses that could improve pedestrian safety and better connect people to mass transit.

The funding is an example of the administration’s efforts to address racial disparities resulting from how the United States built physical infrastructure in past decades. The Transportation Department has awarded funding to dozens of projects under the goal of reconnecting communities, including $185 million in grants as part of a pilot program created by the $1 trillion bipartisan infrastructure law.

But the project in Kansas City also shows just how difficult and expensive it can be to reverse long-ago decisions to build highways that slashed through communities of color and split up neighborhoods. Many of the projects funded by the Biden administration would leave highways intact but seek to lessen the damage they have caused to surrounding areas. And even taking out a roadway is just a first step to reinvigorating a neighborhood.

“Once you wreck a community, putting it back together is much more work than just removing an interstate,” said Beth Osborne, who served as an acting assistant secretary at the Transportation Department during the Obama administration and is now the director of Transportation for America, an advocacy group.