When only 6 percent of San Francisco accounts for nearly half of a city problem, that’s a worrisome imbalance that should be corrected. Those figures reflect the tiny population of the African American residents who account for a disproportionate share of locals arrested for driving with suspended licenses.

The lopsided picture extends across California — and perhaps the rest of the country, too. An analysis delved into a troubling reality on the streets: police ticket writing is heaviest in poor and nonwhite areas and leads to license suspensions and arrests when fines aren’t paid.

The San Francisco totals aren’t unique. In Los Angeles, black residents make up 9.2 percent of the population but account for 33 percent of those arrested for getting behind the wheel.

The results can mar an employment record and job resume. They can lead to jail time and court orders. Running up a traffic ticket, ordinary as that sounds, can have punishing results.

It’s also something else: a slow-burning form of racial injustice that hits African American and Latino drivers especially hard. On one level, it’s not surprising that a low-income driver would skip a traffic fine and court payments even to the point of losing a license. Paying off tickets comes low on the household priority list that includes food and rent.

But the numbers reveal even more. Police stage more traffic stops that lead to tickets in low-income areas than elsewhere, according to a Chronicle data study. The groups less able to pay are pulled over at a greater rate, furthering the spiral of money-fueled trouble.

The pattern, also described in a report by the Lawyers’ Committee for Civil Rights in San Francisco, widens a problem of abjectly unfair traffic fines. Over the past decade, an astonishing total of 4 million Californians received license suspensions after failing to pay ever-rising fines and court fees. The penalty sums, which ranged into four figures in some cases, were quietly boosted by local governments and the courts to aid budgets hit by the recession. Faced with court summons and bills way beyond reach, people without the spare cash ignored the problem and eventually lost their licenses.

The results eventually led Sacramento to rethink the issue and offer a partial amnesty program and a change in rules that once obliged drivers to pay fees before protesting a ticket.

The latest analysis brings another way to look at the unfairness of heavy traffic fines in a state where driving can be indispensable. There’s an unmistakable racial aspect to the issue, one that hits nonwhite drivers harder. That’s an injustice that can’t ignored.