First, to answer the question directly, “Why does God allow this to happen?” Here is what would have to happen if God were to stop these accidents, which he could. Every time that a teenager drinks, speeds or lacks automotive experience and gets in danger, God would have to intervene with a miracle. If they crashed their cars, God would have to “rewind time” just for them, and either raise them from the dead or intervene at every moment that is the “point of no return,” such as forcing the speedometer down so the car cannot go any faster, or having an angel steer the wheel of the car of an inexperienced driver. It would obviously be unmistakable that God is intervening in thousands of lives on a daily basis.
In no time at all teenagers would stop wearing their seat belts, try to put “the pedal to the medal” as hard as they can in order to test how far they can speed, take drugs (to see if God only “fixes it” when they are drinking or if he will “fix” “too much” drug use too). Perhaps an extreme sport would develop where teens would race their cars to see who could get farther before God intervenes and stops the race, or they would even smash into buildings with their cars, to see if God will stop them this time, or raise them from the dead.
You know I’m not exaggerating, even though that may be your first impulse of response. If God were to answer your pleas, literally, to not allow these things to happen to teenagers, he’d have to directly intervene thousands of times a day on a miraculous basis in a way that could not be mistaken and would obviously become widely known, anticipated, and even demanded. Soon those who die in war would wonder why they are not preserved, when they are serving their country, yet teenagers who drink and drive are saved. Then the cancer and heart patients would wonder why God does not fix them, especially if they lived worthy lives and worked for many years, while God is miraculously saving those who drink and drive and now also those who fight in war. People would stop trying to be safe. It is as simple as that. People would stop trying to do better, to be safer, and to be more caring of each other, to be more childlike as children and more mature as young adults. People would soon think that staying alive no matter what one does (and how one hurts others, such as the passengers in a drunk driver auto) is all that matters, and who cares about leading a good life in order to prepare for the eternal afterlife. That is human nature. Look at people who will do anything for a high, inhaling things that outright kill them. Humans have an adrenaline addiction and an immaturity that providing miraculous cures and preventions for each instance would only encourage, not discourage, that behavior. God, in their minds, would not be “Robo-cop” but “Robo-cure,” where youngsters and eventually everyone thinks they can do whatever they want, and then the button gets pressed and God performs a miracle to cure them.
So when people say that it is God’s will that someone dies in such an automobile accident, they mean that it is God’s will that humans have alcohol, roads, cars, children and physical laws that govern mass and energy during impact. It also means that God has foreseen this event, since God is all knowing, and that he is not going to intervene, for precisely the reasons that I described above. Therefore by not intervening with a miracle it is God’s will. But it is not God’s will that a young person drink, drives and dies. How do we know that? The Bible forbids intoxication. It’s as simple as that. If God ever approved of intoxication it would be in the Bible. So when a youngster drinks, drives and causes an accident, he or she is not performing God’s will. It is God’s will that natural law continues to consistently apply when human behavior dictates.
Having said that, I would understand if at that point you think that God must be a pretty chilly character and does not understand your pain. You’d be wrong. God is all knowing and here is what that means in this context. God not only knows your pain, the pain of your loss, but he knows every iota of it now and at every moment in the future, before you even experience it. So God, obviously, being the all-knowing, knows every bit of pain and the effect it has on you from start to finish, “all at once,” as he knows every iota of the future. For example, God knows every tear you shed and will shed, every stress hormone that you emit, every pang of memory that you have, and every change in your health and behavior that you experience, all in advance, until the day that you pass on. This of course is true of everyone, all of the survivors, all of those who mourn, and the impact even on strangers and the community of each passing.
Further, while you can only imagine, and I know this is painful, all that your loved one would have experienced if he or she lived, God actually knows what would have happened in your loved one’s life. God has “the facts” and knows whether they would have graduated, gone to work, gone to college, served in the armed forces, bummed around Europe as a tourist, fixed cars, married, had children, been a grandparent, retired, and so on. So far from being a chilly character, God knows precisely the full cost and lost potential of every single person and knows the grief of that curtailed life.
God himself does not grieve because God encompasses everything, including the eternal that is outside of the boundaries of life, so God, for lack of a better expression, always puts even the saddest loss of life within the overwhelming context of eternity. But God knows humans better than they know themselves, so God indeed knows the grief of a loss to the fullest measure, more than even the parent can comprehend, since God has “all the facts” including the details of “what would have been.” No one, either God or the angels, is “happy” when someone suffers or dies tragically, but remember they are on the other side of the door seeing that person’s immortal soul. It is hard to grieve the loss of a person when that person is there with you. Thus God and the angels feel particular pity and comforting love for those who on earth, alive, suffer the loss of their loved one, and who must still go on. It is then that if one believes, and continues to believe, one can turn to God and know that as Jesus Christ taught, “Blessed are they who mourn, for they will be comforted” (Matthew 5:4).
I hope that you find this helpful. Truly everyone knows that the only help for a terrible loss is the gradual effect of time. I think, though, that talking through the difficulties of God actually intervening in every case such as this is helpful, as I know that people in their pain do not think it through when they wish that God could have saved their loved one. God could do so, but that is precisely the point where humans say to God, “Well, we can’t manage our own business and live without being micromanaged, so make us robots and life will just become one big game of ‘let’s see when God will save us next.’” Remember too that it is not as if God is silent. The Holy Spirit and the guardian angels are constantly encouraging good and safe, life affirming behavior. As I’ve written previously, if one were to conduct an experiment and the Holy Spirit and the guardian angels were removed of their silent influence, life would suddenly be so dark and unbearable that humans would not even be able to stand up. The guiding encouragement of the Holy Spirit and the guardian angels is like oxygen, it is so natural and taken for granted that one would only notice it if it were totally removed, God forbid. All I can say is that parents and loved ones need to band together to reduce the immaturity and bad influences of society on the young, especially in high risk behavior, which they are all so prone to, as many humans are by nature.