Car accidents kill millions of children in the United States and Canada every year. Safety restraints and car seats can save lives if installed and used properly. Every child from birth to about 8 years of age should be correctly secured in a car seat. There are four main types of car seats; rear-facing infant car seat, a convertible car seat (rear and/or forward facing), combination booster seat (forward facing) and a booster seat (forward facing only).

Here are some safety features that are recommended for all types of car seats (except booster seats that use your vehicles seat belt):

• 5-point Harness. Experts agree and studies confirm that this type of harness is safest. The 5-point harness usually gives the best fit and reduces the chance of ejection. T-shields and other shield-type car seats are no longer as widely recommended.
• Wide, Twist-free straps. Avoid harnesses have straps that twist easily. A twisted strap reduces the area that restrains a child in a crash, and this can result in burns or more severe injuries.
• Two-piece chest clips. These can also reduce strap twisting and are usually easier to use. They are often more difficult for a child to detach thus providing a safer ride.
• Front harness adjustments. Some seats have a mechanism on the front of the car seat to adjust the tightness of the harness. Experts recommend that the harness be snug, so that you can't pinch the strap away from the shoulder. A tight harness reduces the forward movement of the head in a crash and reduces the overall risk of injury. The easier the tightness is to adjust, the more likely it is that you will adjust it properly every time (winter coats and other bulky clothing under the harness straps are not recommended).
• Built-in locking clips. A lot of older vehicles will require the use of a metal locking clip to make sure the seatbelt holds the car seat properly and doesn't loosen over time. These clips are easily lost, and often used incorrectly. A few models have built-in locking clips that are much easier to use and often result in a tighter fit.
• Seat Belt Routing Path. In addition to built-in locking clips, some car seats have seatbelt routing paths, which may make for better installations in some vehicles. Certain seats also make it easier to actually route the belt from one side to the other with your hands. Vehicles with sloped rear seats or seatbelt buckles that come out from in front of the crease between the cushion and the back of the seat can make for difficult installations.
• Size. Certain seats are simply too large to fit in vehicles with small rear seating areas, especially when they are rear facing. At least one larger model (Century SmartMove) must remain free to rotate backward in a crash for safety reasons, and in some cases this means it cannot be touching the seat in front of it. For most car seats, this is not an issue, and may even be an advantage in a crash. Finally, it is at times necessary to choose a narrower model so that more car seats or passengers can fit side-by-side in the rear seat.
• Tether strap with easy adjustment. Most new convertible and harnessed front-facing car seats have standard top tethers, and they can be installed on older ones. Tethers improve safety in a crash when installed properly. The mechanisms to adjust the length vary from model to model. Some have an easy-to-use push-button mechanism while others have more difficult slider buckles.
• Rear-facing tethers and Anti-Rebound Bars. These are found on a few infant and convertible seats (Britax Companion infant seat uses one). Depending on the model, these features may improve crash performance, reduce the rebound of the rear-facing seat into the vehicle seat and increase the stability of the installation.