A child restraint system is any device, used in conjunction with safety belts, designed for use in a motor vehicle to restrain, seat, or position children and meets the Federal Motor Vehicle Safety Standards set forth in 49 C.F.R. 571.213.

It may be a child safety seat or harness/vest or booster seat. (The vehicle's safety belts are not a child restraint system.)

An appropriate child restraint system is one that meets the child's height, weight, and size according to the manufacturer's recommendation for that restraint system.

Fines will range from $25 to $100 for violations.

Children under the age of 4 are required to be restrained in a federally approved child safety seat when riding in a motor vehicle. If the weight of a child under the age of 4 exceeds 40 pounds, the child may be restrained in an appropriate child restraint system, allowing the child to use a booster seat.

No. However, children under the age of 4 must be restrained in a federally approved child safety seat when riding in a school bus. Liveries, taxis, and public transportation buses are exempt from the occupant restraint law.

Not necessarily. Choose the restraint system that will fit your child's weight and size. Read the manufacturer's instructions and recommendations for that particular seat. For maximum protection, keep a child in a forward-facing child safety seat with full internal harness until they reach the manufacturer's recommendations for upper size limits. The harness provides upper body, head, and neck protection.

The next step of children who have outgrown a forward-facing child safety seat is a booster seat, usually when a child weighs more than 40 pounds or grows more than 40 inches in height.

There are two major types of belt-positioning booster seats:

1. Backless or low-back booster seats are used in vehicles with a high seat back in which the child's head can be supported by the vehicle seat back or head restraint.
2. High-back booster seats are used in vehicles with a low seat back where there is no vehicle seat back or head restraint to support the child's head and neck.

Booster seats must be used with both the lap and shoulder belt. A booster seat should never be used with a lap belt only.

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 4'9" in height and is about 8 years old. Please make sure that your child meets all of the following requirements for a proper seat belt fit:

1. The lap belt should be low across the upper thighs or hips, not across the abdomen.
2. The shoulder belt should lie across the chest and shoulder, not touching the neck or face.
3. Your child should be able to sit with his or her back straight against the vehicle seat back with knees bent at the seat's edge without slouching.
4. Your child should be able to ride this way for the entire trip.