The car is a common and efficient form of transportation in the US and Europe, but is also considered very dangerous. More than 47,000 people in the US die from injuries related to motor vehicle crashes per year. In addition, 1,800,000 people per year are also permanently disabled. What statistics fail to show is that most of the people that are injured in traffic related accidents are in their 20s. Seat belts and car seats Safety belts and car seats greatly decrease the number of fatal accidents and the chance of motorists involved in crashes requiring medical attention. Belted motorists have around half the chance of an unbelted motorist of serious injury or death. Car seats decrease the chance of injury or death by about two thirds. These show the effectiveness of seat belts and child safety seats. In California, safety requirements jumped from 18% to 47%. The usage of seat belts has risen nationally over time. The combination of these two facts has the great potential of improving public health. It was estimated that if 100% of people in the US used seat belts, 12,000 to 15,000 deaths would be prevented. How fatigue affects driving There is a strong association between fatigue and the risk of a crash. Drivers with less than five hours sleep in the last 24 hours, and driving between 2am and 5am increases the chance of involvement in a car crash by 19%.