I made a chart last night of the day and time of the most recent 5,000 suspended driving cases handled by the Lincoln Police Department:
You can click on the chart for the full size image, which is easier to read. The rows are days of the week, Sunday at the top, Saturday at the bottom. The Column are hours of the day beginning at midnight from left to right. The color reflects the number of cases in each day/time cell from low (light blue) to high (deep red).
I call this kind of chart is known as a temporal heat chart, or a temporal grid, and I’ve published several of these on my blog over the years. This one is meant to show when suspended drivers are most often driving, or more specifically, when they are being caught. It’s not on the way to school or work. Rather, it appears to be on the way home from bars.
The relationship to alcohol is hard to ignore. You will notice that it shows a similar pattern to this temporal heat chart of violent crime, which I published seven years ago (although the former reverses the column/row arrangement.) It also looks quite similar to this one from four years ago depicting DWI arrests.
All of these–suspended drivers, violent crimes, DWI arrests–are very different than this one, which shows over 30,000 traffic crashes, and reflects the density of traffic during the weekday rush hour.
The concentration of suspended drivers in the wee hours of the morning on drinking days may in part be caused by the nature of police activity. These are the times officers are most likely to be looking for drunk drivers, and in the process finding suspended ones as well. Or, the concentration could be caused by the fact that these are the times suspended drivers are more likely to be on the road, or more likely to be driving poorly and drawing the attention of the police.
This post was originally published on March 18, 2016 on Director Casady’s blog.
