No Correlation Between Race, Poverty Level, and Speed Safety Camera Tickets
Myth: Speed safety cameras disproportionately issue tickets to low-income people of color.
Fact: This is not true in New York City. There is no correlation between the number of speed safety camera tickets issued and race or poverty level.
Here’s the data we’re using
Transportation Alternatives’ research team used data made available by New York City to get the total number of speed safety camera tickets issued in each ZIP code.
Next, we wanted to see how many tickets were issued per resident. To analyze the fairness of their placement, we looked at the total population of each ZIP code, as well as their racial demographics and population living in poverty.
Then what?
To see if there was any correlation between violations per resident and any demographic variable, we had to find the R2 (referred throughout as R2) number. This is basically a fancy way of explaining how much correlation there is between two variables: to what extent does each point adhere to the general trendline?
First, let’s explain what R2 means. It’s a number between zero and one, with zero representing pure randomness and one representing a perfect 1:1 correlation. An R2 value above 0.7 indicates that the two variables are correlated; above 0.9 is considered strong correlation.
You can also think of R2 like a percentage: two variables can be zero percent linked (R2 = 0) to 100 percent linked (R2 = 1), and are considered uncorrelated below 70 percent (R2 = 0.7).
It can be visualized on a graph, like to the right: R2 is the degree of variance of the data points from the trendline.
So what did the data show?
The data shows that there is absolutely no correlation between any of the demographic variables and the number of speed safety camera tickets issued per resident in a ZIP code.
Each of the demographic variables scored far below the R2 = 0.7 threshold to be considered correlated, or 70 percent.
The highest R2 value, measuring the strength of the rate of car-ownership’s connection to the number of speed camera tickets issued per resident in a ZIP code, was 0.081 — just 8 percent, when 70 percent is the bar for correlation.
The percentage of Black residents in a ZIP code had absolutely no correlation with speed camera tickets issued per resident, with an R2 value of 0.002 (0.2 percent).
The percentage of non-white and white residents both had zero correlation with speed camera tickets per resident, with R2 values at 0.00008 (0.008 percent) and 0.00003 (0.003 percent).
The percentage of residents in poverty had no correlation with speed camera tickets per resident, with an R2 = 0.048.
New York City’s speed safety camera program saves lives. The program led to a 72 percent reduction in speeding and a 55 percent drop in all traffic fatalities at camera sites during hours of operation after its introduction. There is no correlation between the number of tickets per resident and race or poverty level.
All That Said
While there is no evidence of racial or class bias in the tickets distributed by New York City’s speed safety camera program, there is a wealth of evidence that low-income communities, immigrant communities, and communities of color have suffered under decades of disinvestment in transportation infrastructure and the harmful aftereffect of generations of racist and classist planning practices which mapped high-speed, high-traffic roads through these residential neighborhoods.
The result is disproporation rates of traffic deaths and injuries, asthma, heat-related fatalities, preterm birth, and a wealth of other harms — physical, emotional, and financial.
Streets in these communities often have more and wider lanes, less traffic calming, and less safe streets infrastructure like crosswalks, protected bike lanes, medians, and more. Reckless driving behavior such as speeding is therefore more likely on these streets — which were designed with the purpose of moving traffic and with no consideration of the people who needed to live, walk, shop, and play in their vicinity. Small, automatically-distributed financial penalties have shown to be an effective tool to change driver behavior in these streets, such as the $50 ticket given to offenders who drive at least 11 mph over the speed limit by New York City’s speed safety cameras. However financial penalties, which disproportionately affect low-income people, are a Band-Aid, not a long term solution to the problem.
Traffic engineers know how to design streets to prioritize safety and driver compliance. Speed safety cameras, and all automated enforcement, should not be considered a long-term solution but a stop-gap protective measure en route to the wholesale citywide redesign of streets for safety.
