Which criterion indicates it is safe to discontinue booster seat and transition to a regular seat belt without a booster?

• A. The child is at least 6 years old
• B. The child can buckle themselves without assistance
• C. The child has perfect posture in the car
• D. The lap belt sits across the hips and the shoulder belt crosses the chest comfortably

Answer: (D)

The crucial factor is how the seat belt fits on the child. A booster is used to position the belt so it protects the body correctly in a crash, and you can discontinue the booster once the regular seat belt fits properly without it. The proper fit means the lap belt lies low and snug across the hips or upper thighs, not the stomach, and the shoulder belt crosses the chest and sits comfortably on the shoulder, not cutting into the neck or slipping off the shoulder. This positioning helps distribute crash forces across the strongest parts of the body—the pelvis and chest—reducing injury risk. Age, ability to buckle independently, or merely having good posture don’t guarantee a safe belt fit, because the belt can ride up or sit in the wrong place even if those factors are present. Therefore, the described belt positioning is the best indicator that it’s safe to stop using a booster.