How do you react when you read the following sentence?

In Los Angeles, 92 percent of bus riders are people of color.

This supposedly shocking fact is the starting point for Amanda Hess's confused and aggravating piece in the Atlantic today, which argues that somehow transit is failing because it's not attracting enough white people. "As minority ridership rises, the racial stigma against [buses] compounds," Hess writes. Sounds alarming! But who exactly is feeling this "stigma," apart from Ms. Hess, and how many of those people are there?

Read it again:

In Los Angeles, 92 percent of bus riders are people of color.

Now, how does your reaction change when I point out that in the 2010 census, just under 28% of the population of Los Angeles County is "non-Hispanic white," so over 70% can be called "people of color." Now what if I tell you that as always, transit is most concentrated in the denser parts of the county, where the demand and ridership are higher, and these areas happen to be even less "non-Hispanic white" than the county at large? (Exact figures can't be cited as this area corresponds to no government boundary.) So the bus system, weighted by where the service is concentrated, serves a population of whom much, much more than 70% could be described as "people of color".

Please don't treat these figures as too precise. The claim that "92% of Los Angeles bus riders are people of color" is impossible to fact-check because two of its key terms are ambiguous.

Does "Los Angeles" mean the City of Los Angeles or Los Angeles County? They're both big but very different. Remarkably, though, both are over 70% "people of color."

Likewise there are many definitions of "Los Angeles bus rider" depending on which transit agencies you include. I suspect Hess got her figure by looking just at LA Metro, rather than the many suburban operators who are also part of the total Los Angeles bus network, but it's hard to know.

And by the way, I'm assuming that "people of color" include what the Census calls "Hispanic whites," as it has every time I've heard the term. (To the Census, anyone of European ancestry, including from Spain centuries ago, is "white.")

So to the extent we can track Hess's statistics here's what they say: Los Angeles bus ridership is mostly people of color because Los Angeles is mostly people of color.

But Hess wants the nonwhiteness of Los Angeles bus riders to be a problem, evidence that the transit agency — at least on the bus side — is somehow failing to reach out to white people.

Racism has sometimes had a role in the history of U.S. transit planning, and there's a Federal regulatory system, called Title VI, devoted to ensuring it doesn't happen again. But racist planning — discriminatory service provision aimed to advantage or disadvantage any ethnic group — is not only immoral but also a stupid business practice. Diversity is the very essence of successful transit services — not just ethnic diversity but diversity of income, age, and trip purpose. Great transit lines succeed to the extent that many different kinds of people with different situations and purposes find them useful. As a planner, I want every line I design to be useful to the greatest possible range of people and purposes, because that ensures a resilient market that will continue even if parts of it drop out for some reason.

So why is it a problem that in massively diverse international cities we don't have "enough" white people on the bus?

I happen to be in Los Angeles at the moment, on a brief and busy trip. Tonight, after dark, I took a pleasant walk across downtown — from Union Station to 7th & Flower — pausing to note how safe I felt on streets and squares that were synonymous with crime and violence when I was a child. Few of the people I saw were white like me, but the folks relaxing and listening to music in Pershing Square seemed like citizens of a decent city capable of joy. (In a mean moment, I wanted to call my late grandmother and say: "Hi, Gramma! It's 10 PM and I'm in the middle of Pershing Square!" I wanted to see the look on her face, back in 1980 or so. She would probably have called the police and demanded they rescue me.)

Then I took the bus back to my Chinatown hotel, Metro Line 78, well after dark, and marveled at all the dimensions of the diversity. Some people looked poor, others seemed prosperous and confident, but a strong social contract was obvious. I read clues suggesting a huge range of professions, situations, life choices, and intentions. And if Amanda Hess hadn't been so insistent about it, the fact that I was the only white person on the bus wouldn't have occurred to me, and certainly not occurred to me as any kind of problem.

Yes, there are plenty of people, still, who feel more comfortable riding with people who look like them, in a vague way that encompasses both race and class signals. But how much does this desire influence service planning? How long should it? Questions worth debating, I suppose.

Among young people out in downtown Los Angeles at night I see mostly interracial groups of friends. I have no illusion that the whole city is like this, but it's striking nonetheless. About 18 years ago in the New Republic — too old to be linkable — I read a story about how "post-racial" young people in Los Angeles are, how they are used to cultural diversity and uninterested in racial divides. If any cultural observer could discern that then, how much truer it must be now.

Go ahead. Try riding one of the well-lit, air-conditioned buses of inner Los Angeles. It's not full of people just like you. But neither is the city, and that's the glory of it.