FOUR YEARS OF NYC CAR ACCIDENTS
Thanks to the Open Data initiatives in NYC, I was able to get a very detailed dataset of all motor vehicular incidents in the city from 2012 to the current day. Each dot is a car crash and each red dot resulted in a fatality. The size of the red dots corresponds to the number of people that were killed as a result of the accident.
THE big picture
From a birds-eye view, you can see that less accidents happen around the holidays, during midnight to 6AM, and most surprisingly between 3-4PM. I had to check my code and make sure it was not a bug. I remember seeing some work around shift changes in NYC, and then decided to look into public service shift changes, specifically police officers.
It turns out that the NYPD Shift Changes directly correlate with that low density band in the middle of the day, and harder to see, but with the same type of band between 7-8AM. There's no reason to believe that less accidents happen during that time, so it's fair to infer that the changing of the shifts impacts the reporting and input of these cases into the NYPD databases.