IIHS Booster Car Seat Safety Ratings
The IIHS study is actually measuring seat belt fit in booster car seats. It's important to note that these are not crash tests. The actual structural integrity of the booster car seats, or their crash-worthiness, is not being measured at all in these IIHS tests. What IIHS has done is placed a child-size crash test dummy in several booster seat models and measured the seat belt fit based on their parameters for what optimal seat belt fit should be.There are helpful facts that come out of the IIHS booster car seat tests and ratings. First, it's wonderful to draw attention to the fact that seat belt fit is very important. After all, the whole point of a booster car seat is to raise the child up so that the adult-size seat belt can fit properly. If the booster seat isn't providing a good seat belt fit, it's nearly pointless. Improperly fitted seat belts can even cause some additional types of injuries during a crash when the belt hits soft parts of the body instead of the stronger bones it's meant to be in contact with. So, it's great that the IIHS study makes the point that seat belts must fit properly.
These fit ratings also help identify types of booster car seats that might need some improvement in order to fit a larger number of children properly. Since all children are not shaped the same, and grow at different rates, it's important to have booster car seats in a lot of different shapes and sizes to accommodate all of those kids. Manufacturers should be careful to balance the real life needs of children of various shapes and sizes when making changes based on the IIHS fit rating information.
I also like that IIHS has tested the booster car seats in various vehicles. This highlights the point I, and many child passenger safety advocates, have made for years, that whichever car seat you choose must fit your vehicle. Not every booster car seat will work perfectly in every vehicle, due to seat belt configurations and vehicle seat shapes and sizes.
That said, I do not think that the IIHS booster seat safety ratings are the definitive ranking of which boosters are safe, nor do I think you need to immediately throw away a booster car seat if it got a "poor" rating from IIHS. Here's why.
- Real children are not crash test dummies. They are not all perfectly sized to the "average 6 year old," as the dummy is that was used in the IIHS tests. Children of different sizes and shapes will fit booster car seats differently.
- It is more important to look at how the seat belt and booster fits your child in your vehicle than to rely on a fit rating from a third party.
- The IIHS tests do not take into account the real world crash statistics that show that booster car seats are performing well in actual crashes.
How to Check Your Child's Booster Car Seat for Fit
- Have your child sit in the booster car seat.
- Buckle the lap-shoulder seat belt according to instructions.
- Make proper adjustments to the headrest or shoulder strap positioner.
- Check to see if the lap portion of the seat belt is low and tight across your child's upper legs or thighs. The seat belt should not be up on the child's stomach.
- Check that the shoulder portion of the seat belt is on the shoulder bone, about halfway between the neck and outer shoulder. This part of the seat belt should not creep up on the child's neck or be way out over the edge of the shoulder.
- Proper positioning of the lap portion *and* the shoulder portion of the seat belt means the booster car seat is a good fit for your child and your vehicle.
If you've checked the fit of your child's booster car seat and the seat belt does not fit well, that actually is a good reason to look at different booster car seats. The booster you choose doesn't have to be expensive. Above all, the booster seat just needs to fit properly.
If you have a child younger than age four in a booster car seat and the fit is poor, I'd suggest looking for a high-weight-limit combination car seat and booster (not a 3-in-1, since they often have 40 lb harness weights). That way, you can use the harness a while longer until your child is larger and more ready to fit into a booster seat and seat belt. It is often difficult to find a true booster car seat to properly fit a child under age four since they're just not big enough yet.
