Experts agree that even when external factors are applied, human error is responsible for most car accidents, at least to some degree. Most people equate human error with drunk driving, speeding or distracted driving, and while these certainly are leading causes of crashes, they are not the only ones. Here are a few facts about car crashes that may surprise you:

1. Rubbernecking: According to a 2003 study by Virginia Commonwealth University Transportation safety Center, rubbernecking was the number one cause of car accidents that year.
2. Driver Fatigue: Lack of sleep can have a profound impact on any driver. According to the Department of Transportation, staying awake for 18 hours in a row is equivalent to having a blood alcohol content of 0.08 percent.
3. Night Driving: Reduced visibility and fatigue can make it much more difficult to stay alert, and to judge speed, distance, and depth. The DOT recommends that you avoid driving between midnight and 6 a.m. because of reduced visibility, and between 2 and 4 p.m. because so many people suffer reduced energy levels at that time of day.
4. Aggressive Drivers: Some drivers act as if they own the road with little regard for the safety of others. These drivers often fail to yield, change lanes frequently, fail to use turn signals, ignore traffic signs, tailgate other vehicles, and even verbally abuse other drivers. Their actions can be annoying and very dangerous. In 2011, speeding (a form of aggressive driving) was a contributing factor in 30% of all fatal crashes.
5. Teenage Drivers: The primary danger with teenage drivers is their lack of experience, which can lead to poor decision-making. Teens are more likely to speed and not use their safety belts. In fact, the Centers for Disease Control and Prevention states that car crashes are the number one cause of death for teens in the United States.
6. Poor Car Maintenance: Poor vehicle maintenance on the part of the owner can be a major cause of car accidents. Drivers should check lights, tire tread and pressure, and brake pads and lines on a regular basis. Avoid making modifications to your vehicle without the supervision of a professional. Brake failure can contribute to up to 5% of accidents a year.