America’s suburbs, now as diverse as large central cities were 30 years ago, are repeating the cycle of racial segregation and inequality that have haunted major cities for decades.

Ferguson, Missouri, a stark example of this suburban transformation in the St. Louis area, is at the heart of coast-to-coast demonstrations and a racially charged national debate over the relationship between police and black communities. And Ferguson may well be the first suburb to ignite unrest.

Protests that spark rioting have rarely started in suburbia and have almost always begun in major central cities, such as in Detroit (1967), Washington (1968) and Los Angeles (1992).

But in 2014, America’s suburban landscape has clearly changed.

“[It] isn’t a St. Louis ghetto,” segregation expert John Logan said of Ferguson, a suburb with about 21,000 people, more than two-thirds of them African-American. “It’s out in the suburbs, and it’s not the worst neighborhood, so why are people so steamed up?” Logan asked. “There is a high degree of segregation and steering in the housing market and divisions across racial lines.”

Logan, a Brown University sociologist, shows just how deep the divisions are in a new report, “Separate and Unequal in Suburbia,” out Wednesday.

He found that, despite a decline in racial segregation and improvements in incomes marked by the rise of the black middle class, blacks and Hispanics continue to live in the least desirable neighborhoods — even when they can afford better — and their children attend the lowest-performing schools.

The findings come as unrest continues from New York to Los Angeles over last week’s decision by a grand jury not to indict Darren Wilson, a white Ferguson police officer, in the shooting death of Michael Brown, an unarmed black 18-year-old, in August.

Logan’s research further dashes hopes of a postracial America.

“Moving to the suburbs was once believed to mean making it into the mainstream,” he said. “There is something to this idea that moving on out is moving up … Yet minorities are not finding equal access to the American dream.” When neighborhoods where blacks live are compared with those where whites or Asians live, “the inequality is quite stark,” he said.