At what age must a child be in a car seat until?

The correct answer is that a child must be in a car seat until they are 4 years old due to child passenger safety guidelines. These guidelines are based on research that indicates the best way to protect children in the event of an automobile accident is to use age-appropriate restraints.

Children under the age of 4 are generally not big enough to be safely secured in standard seat belts; thus, it is essential for them to use a car seat designed for their size. Once a child reaches the age of 4, they can transition to a booster seat, provided they meet weight and height requirements for that type of seat.

It's important to adhere to these recommendations, as statistics show that proper use of car seats significantly reduces the risk of injury in accidents. The transition from a car seat to a booster seat after 4 years, and ultimately to a seat belt, should be made in accordance with the child's size and developmental readiness to ensure maximum safety while traveling.