• Alert your teens. Encourage them to pay extra attention to driving situations—such as commuting and driving at night—that tend to be most dangerous.
• Make an agreement. If you and your teen co-author a driving agreement, one of the stipulations on it may be that they must get a minimum number of hours of sleep the night before. According to a 2008 survey of 3,580 students by Liberty Mutual and SADD, teens who had gotten fewer than eight hours of sleep were twice as likely to say they have fallen asleep at the wheel (20 percent) than those who had gotten eight or more hours of sleep.
• Encourage them to speak up. Help your teen figure out how to speak up when friends aren't driving safely. A recent national study by Liberty Mutual and SADD revealed that only about half of the teens surveyed would ask another teen driver to stop distracting behavior like racing other cars, texting or using a cell phone. But when they were in the driver's seat, they were overwhelmingly likely to stop distracting behaviors if asked to by another passenger.