By David M. Greenwald
Davis, CA – Before the Nextdoor admins removed the discussion there was an interesting engagement on the issue of a supposed police speed trap on Covell and Anderson. Given that speed traps are not legal in California, I assumed that they simply meant they were cracking down on speeding vehicles.
My concern that I expressed on the site, before it was all removed, was that increased enforcement would mean a disproportionate crackdown on Black and brown populations.
Even in places like Davis—even facing clear and unambiguous stats—you get the same responses when you point this stuff out.
The first is the idea that the people they catch are simply lawbreakers. If Black and brown people, by extension, are being disproportionately pulled over, that would mean they are speeding disproportionately.
The problem, as I tried to point out, is if you camp yourself out at a location with free-flowing traffic, you will have tons and tons of speeders. How do you decide whom to pull over? Many would say the most egregious violators. To some extent, you will see that. But most of the drivers pulled over with crackdowns are not being chosen in an objectively reckless manner. Those are notable and noticeable, but relatively rare.
This is the problem—if half of the traffic is committing a moving violation, and a good proportion is exceeding the speed limit by at least five to ten mph, whom do you stop?
We know the answer to that because we have the data. We have data in Davis and data that is universal. In Davis, we know that Black and brown people are about six times more likely to be pulled over than whites.
And, in a lot of these cases, they are not issued tickets. In fact Blacks, for example, in Davis as elsewhere are more likely to be pulled over and stopped, less likely to be issued a ticket for a moving violation, more likely to be searched and, once searched, less likely to be found in possession of contraband. (Since I’ve made this point many times, not going to regurgitate the stats, google it though).
So what was the response?
One of the points made in response many times is unless you are right next to the car, it’s hard to tell the race of the driver.
We have data that disproves this as well.
In May of 2020 (before George Floyd and some of the other incidents, by the way), the Stanford School of Engineering released the largest ever study of racial profiling during traffic stops (link).
They analyzed 95 million traffic stops filed by officers with 21 state patrol and 35 municipal police forces (in other words, nearly half the states and 35 cities across the nation), over an eight-year period from 2011 to 2018.
“Researchers concluded that ‘police stops and search decisions suffer from persistent racial bias.’”
But, more than that, they found “blacks, who are pulled over more frequently than whites by day, are much less likely to be stopped after sunset, when ‘a veil of darkness’ masks their race.”
What does that tell you? It tells you that, contrary to what ordinary residents can tell, the police really can tell the race of the driver when they pull them over.
That doesn’t surprise me because when I have ridden on ride-alongs—many of them over the years—police officers really see things that I don’t or can’t.
I used to think it was probably make and model of the car, and it may be some of that. But obviously, that difference would not disappear at night.
There really isn’t a good counter-hypothesis here. The volume of data and the starkness of the difference is overwhelming.
We are talking about hundreds of thousands of data points here.
“Because they had such a massive database, the researchers were able to find 113,000 traffic stops, from all of the locations in their database, that occurred on those days, before or after clocks sprang forward or fell back, when the sky was growing darker or lighter at around 7 p.m. local time.
“This dataset provided a statistically valid sample with two important variables — the race of the driver being stopped, and the darkness of the sky at around 7 p.m. The analysis left no doubt that the darker it got, the less likely it became that a black driver would be stopped. The reverse was true when the sky was lighter.”
The response on Nextdoor was a bit of data denial. There is a reason you run multiple regressions in studies like this and collect a huge amount of data to avoid the kinds of pitfalls people tend to cite. Here they use a logit model, modeling for the probability that a stopped driver is Black at a certain time, location and period of year. (Read the whole study here—but, warning, the math will be obnoxious for the casual reader).
One person argued that they had no agenda here—other than a confessed desire to make streets safer, and that’s undoubtedly true. Systemic racism does not generally arise from racist motivations, but rather from practices that over time have been shown to produce biased results.
I have no problem with cracking down on speeding. But if the data show a disproportionate impact on Black and brown people—as the data have shown with police stops—that might suggest that there is a problem here.
We don’t solve this by denying that there was a problem—and unfortunately, Nextdoor didn’t help things by removing it.