Because crash rates are highly elevated during the first months of licensure, it is advisable for parents to limit teen driving so that teens can gain independent driving experience under less dangerous driving conditions. This report describes the effect of the Checkpoints Program on parent limits on novice teen driving through six months post-licensure. Nearly one-quarter of all Connecticut teens who obtained a learner's permit over a 9-month period were recruited, providing a final sample of 3,743 who obtained licenses within the next 16 months. Families were randomized to the intervention or comparison condition. Intervention families received by mail a series of persuasive communications related to high-risk teen driving and a parent-teen driving agreement, while on the same schedule comparison families received standard information on driver safety. Families who participated in the Checkpoints Program reported significantly greater limits on teen driving at licensure, 3-months, and 6-months post-licensure. However, there were no differences in reported risky driving behavior, violations, or crashes. This is the first statewide study testing the efficacy of the Checkpoints Program. The results indicate that it is possible to foster modest increases in parental restrictions on teen driving limits during the first six months of licensure using passive persuasive communications, but that the levels of restriction obtained were not sufficient to protect against violations and crashes.