Final answer:
Children should be using seat belts or a correctly installed child restraint system when traveling in a vehicle to ensure their safety and reduce the risk of injuries.
Step-by-step explanation:
When traveling in a vehicle, children should be using seat belts or a correctly installed child restraint system such as a booster seat or an age-appropriate car seat. These safety measures are crucial for protecting children in the event of a collision or sudden stop, reducing the risk of injury or harm. Adult-sized seats are not suitable for children as they may not provide proper support and restraint.