In the society that we live in today there are more than a few types of impaired drivers, with it either being drugs, alcohol, distracted driving, or fatigue. However all of those contribute to deaths around the world but the most common is people driving while distracted or while being fatigued. Unfortunately those are the two that have the least amount of awareness about them. I feel like we are giving so much attention to, “do not drive while under the influence of drugs or alcohol" but most of the crashes are caused by distracted drivers or fatigued drivers. It's very taboo to drive while under the influence but so normalized to drive while texting or looking at a phone.
I would say that out of both distracted or fatigued, distracted is the most important because it can happen at any time of the day without much thinking about it. For example, one of my friends was driving back to his house and almost got into a car accident, because he was looking down at his phone to check the lyrics to a song. When he glanced down he didn't see that the car in front of it had stopped and he had barely enough time to brake for his life. This happens so often when people think that they can just look at their phone for a second and nothing bad will happen. However, in that one minute that it takes to unlock the phone and do what they were intending on their phone, the person in front of them could have braked and the person on their phone was not watching and smashed into the person that braked. These little pauses in driving to check the phone may seem minute and like they may not happen often, but they cause accidents all of the time. This could be in part to the fact that the distracted driver has done it before and it was fine, no accident, but it only takes one time to end a person's life. 
When I was first starting to drive I had a strong amount of misplaced confidence about my driving abilities. A little bit of context is I live down a dirt road that spans for about half a mile, with a metal fence next to it. So one day a few months into getting my license I'm driving down that road and get a phone notification and decide to look at it. I'm on my phone for a few seconds until I hear several thumps one right after the other. I look over and I am riding along the fence, and my side view window is hitting the fence repeatedly. I urgently spin my wheel to get back on the road. I then promptly put my phone down and shamed myself for being so dumb to get on my phone instead of watching the road and paying attention to what was going on right in front of me. 
Another big reason for car accidents across the United States in teen driving is fatigued driving. That is when someone is too tired and unable to keep their eyes open or happens to fall asleep on the road instead of paying attention. I once asked my friends who got into accidents what the cause was and fatigued driving was most of their answers. This happened when they came back late at night and were trying to get home at the end of the night. Once, my friend got into her car at the end of the event she was at, and did not realize how tired she was until it was too late. And she had totaled her new car, no one was injured besides a few scratches on her and her ego. 
The main problem with these is it does not require a big cognitive deliberation like with drinking or doing drugs. Where you know it is wrong to drive inebriated like that but still do it anyway. These are smaller decisions where one thinks to themselves, “I probably should not drive right now when I am this tired, but oh well it is only ten minutes until I get home,” or “this text will only take a second.” Therefore they are simpler to accomplish. There is more planning that goes into getting drunk than getting behind the wheel. There are also more ways to avoid driving when under the influence, you can have a friend drive or call a car service. Whereas the act of driving while tired or distracted doesn’t seem to be that bad until you are getting into an accident. Whenever you feel like taking your eyes off the road or feel like you’re able to stay awake, don’t. You may succeed once or twice but it only takes one time to not see the brake lights or fall asleep. It only takes a moment to ruin your life or killing someone and ruining others  around their lives