Friday, March 18, 2016

Time of offense

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).

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 then 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 al 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.


Anonymous said...

The week end is not much of a surprise. The areas that are strange to me are the slight rise on Wens, Thurs, Fridays at 10am and 8pm. What do you think is the cause of that? And have you ever checked to see how many of these arrests are of repeat offenders and what they were ultimately convicted of?

Anonymous said...

Would my honorable friend agree that if one's windshield was too frosted to see what lies ahead of their car, perhaps that driver should have moved their lazy backside out to their car a minute or two earlier and scraped the frost away before driving, or even idled for a couple of minutes until their defroster was effective?

Anonymous said...

For those that say this is a "Victim-less" crime hopefully read this article. Suspended/Revoked license ties in with DUI and other reckless habits. It'd be interesting to see how many drunk drivers actually had insurance at the time of the accident. I would bet that more than 90% of these suspended/revoked license drivers don't have any form of auto insurance. This means some poor soul is heading home from a job and is happy he/she has liability insurance along with a valid drivers license gets his/her vehicle totaled by someone with a suspended/revoked license and no way to pay for the vehicle. Glad LPD is doing something about this.