It’s no surprise that distracted driving is a major cause of car-related injuries and deaths. In fact, it’s estimated that roughly 25% of motor vehicle accident fatalities are a result of distracted driving.

But what causes us to be distracted while driving in the first place? A Pennsylvania-based insurance company examined data from the Fatality Analysis Reporting System, which surveys all American motor vehicle fatalities.

The results reveal the top ten causes of distracted driving, and make it clear that not all distractions are created equal.

1. Smoking related– 1%. Only one in a hundred accidents is related to lighting a cigarette, smoking or putting it out.
2. Moving objects – 1%. Moving objects in the car such as insects and pets can lead you to take your eyes off the road—and at least one source suggests that it may be an underreported cause of distraction.
3. Using devices/controls to operate the vehicle – 1%. Surprisingly, adjusting things like mirrors or seatbelts plays a relatively minor role in distraction-related car accidents.
4. Adjusting audio or climate controls – 2%. Fiddling with the radio or adjusting the A/C for even a moment is a factor in a small number of traffic fatalities.
5. Eating or drinking – 2%. Every car has cupholders—and using them can be a definite source of distraction.
6. Using or reaching for a device brought into the car – 2%. We all know that using devices like cellphones can take our minds off the task of driving. But it turns out that even reaching for them can lead to a serious accident.
7. Other occupants – 5%. Other people in the car can place major demands on your attention when you’re driving, which can result in a collision.
8. Outside person, object or event – 7%. It turns out that looking at something or someone outside the car, like gawking at an accident or at people in other cars, is even more of a distraction than the person in the passenger seat.
9. Cellphone use – 12%. The second-leading cause of deaths due to distraction-related car accidents won’t be a surprise to anyone, as cellphones while driving (even the hands-free options) can distract us in a number of ways. But if they’re not the biggest cause then what is?
10. Generally distracted or “lost in thought” – 62%. By far the biggest cause of distracted driving fatalities is a driver’s mind wandering for long enough to lead to a collision—and someone’s death.

Though these 10 factors have a vastly different rate of occurrence, what’s interesting is they all have one thing in common. The one factor in every distracted driving accident is drivers paying attention to something other than driving. So what causes so many drivers to feel they can take their eyes and mind off the road?

There’s a simple but dangerous answer: complacency.

After you’ve been driving for a while you get comfortable and can forget just how dangerous it can be—because you’re complacent to the risks of driving. As a result, you’re more likely to think that you can send a quick text or daydream without putting yourself in danger.

Compounding the problem are other states of mind like rushing, frustration and fatigue. These can further contribute to taking your eyes and mind off the task of driving and influence your decisions to do things when driving that increase your risk of a collision.

So what can you do about it? Check out this free guide on distracted driving that examines why we’re so distracted when behind the wheel—and what we can do about it.

The guide collects the best research on distracted driving and provides an interesting new model for understanding distracted employees in the workplace. Discover an effective framework for improving focus and reducing distraction.

You can download the Driving Distraction Away guide here.