It's hard to know what is the best thing to do for your child when it comes to car seat safety, which is why we want to direct you to your individual state's laws.
According to the IIHS:
All 50 states and the District of Columbia have child safety seat laws. Child safety seat laws require children to travel in approved child restraints or booster seats and some permit or require older children to use adult safety belts. The age at which belts can be used instead of child safety seats differs among the states. Young children usually are covered by child safety seat laws, while safety belt laws cover older children and adults.
Click on the car seat law clickable map below to determine what car seat laws exist in your state:
You can also click here for a car seat law chart sorted by state.