Children under the age of 4 and weighing less than 40 pounds must be in approved child safety seats. Children ages 4, 5, 6, and 7 must be properly secured in an appropriate child restraint system, such as a child safety seat, harness/vest, or booster seat. Seat belts are not designed for children under a height of 4 ft., 9 in. and do not protect small children. Your child should stay in a booster seat until the adult seat belt fits him or her properly. This is usually when your child reaches 4 ft., 9in. in height and is about 8-years-old. All passengers under the age of 16 must use seat belts. All front seat passengers, including the driver, are required to use a seat belt.