The question posed in the title may seem like a no-brainer, and that’s because car accident are ubiquitous and easily written off as being caused by “human error.” However, there are some very specific causes to car accidents that were identified by a 2008 study by researchers at the University of Michigan. They looked at 6,950 crashes to try to figure out why these wrecks happen.

Here are a few of the big reasons why crashes happen:

  • One broad reason is fatigued driving. If you want to call it sleepy driving or drowsy driving, that works too. But the reason is a general inability of the driver to react in a timely manner to the road in front of him or her. Being tired means you aren’t able to operate a vehicle as safely as you could had you gotten enough sleep.
  • Another reason is poor driving, such as losing control of your vehicle (due to dangerous driving habits) or not leaving enough space between you and the vehicle in front of you. Distracted driving is another critical reason why many accidents occur.
  • A more specific reason is turning right at a red light without fully stopping. This type of accident accounts for 6 percent of pedestrian fatalities. This occurs because this behavior leaves drivers with a lack of time to identify people to their right, since they are so consumed with finding out if cars are coming from their left.

Source: Slate, “Anatomy of a Car Crash,” Steve Casner, Nov. 21, 2017