Side Impacts and Booster Seats: A Scary New Combination?


Child Passenger Safety Technicians teach parents “best practice” when it comes to keeping their kids safe. If there’s going to be a crash, we want the best possible outcome. It’s long been an issue for CPSTs that some belt-positioning booster seats have minimum weight limits of 30 lbs. because it encourages parents to put smaller, often younger children in them. ProPublica released an article today on side-impact testing at Evenflo that shows why we need a national side-impact testing standard and why best practice is so important for safety.

Child restraint manufacturers perform their own safety testing, both for regulatory purposes and for research purposes. Back in the early 2000s, the National Highway Traffic Safety Administration (NHTSA) was required to design a side impact test. That never came to fruition, so manufacturers who do side-impact testing created their own “standard” based off this design (see our article here). Side-impact crash testing, like any crash testing, is scary to watch. It’s the nature of the beast, so to speak, that a body will wrap around the seat belt during a crash, so seeing footage like what ProPublica provided is terrifying but not out of the ordinary.

By having their own tests, manufacturers can use marketing terms such as “Side Impact Tested,” “ProtectPlus Engineered™,” “Air Protect®,” and so on. If you’re an educated consumer, you’ll know to look past what might be no more than a marketing ploy to find the seat that fits your child, child’s developmental level, and vehicle best.

Let’s say you’re in the market for a new restraint and you’re not sure if you need a harnessed seat or a booster seat. Your child is preschool-aged (3-5) and in that 30-40 lbs. range. That’s a really tough age and weight range! You want them to be a big kid and have some independence, but really, their bodies are still small, and their impulse control is often underdeveloped. Best practice says a harnessed seat is the best choice for them. NHTSA and the American Academy of Pediatrics both recommend that a child outgrow the weight and height limits of a harnessed carseat before moving to a booster seat. Since most harnessed restraints have weight limits over 50 lbs. now, it’s usually not an issue for many kids to remain harnessed until they reach an age where they’re mature enough to sit well in a booster seat.

Booster seats seem like an easy choice for many parents and caregivers because they’re often lighter than harnessed carseats, easy to move from vehicle to vehicle, give kids independence in buckling (eventually!), and are the last step in “babyhood.” However, that last step is a step down in safety if you make the move too soon for your child. Regardless of the brand of booster you select, make sure that your child:

  1. Has the maturity to sit still in the seat belt with correct fit for a whole trip
  2. Is over the minimum required weight—40 lbs. is a good minimum guideline if you’re still unsure
  3. Meets the minimum age requirement for the booster—at least age 4 for some, although we like kids to be older than that for maturity reasons.

If your child has outgrown their convertible carseat but still isn’t mature enough for a booster seat, a combination harness/booster seat is the answer. This type of child restraint typically has a harness with higher harness slots than convertible carseats, then converts to a booster seat later on. Our favorites include:

Britax Grow With You

Chicco MyFit and MyFit LE

Graco Nautilus SnugLock

Remember, no booster can protect a child in every type of side-impact crash, especially severe ones. This is even more likely if the child is leaning forward, has squirmed out of the belt or even if their head is tilted forward to look at a device at the time of the crash. Any of these issues can cause the child to lose the benefit of the side impact wings and other side-impact features on any brand or model of booster seat. That is why we recommend using a 5-point harness system over a booster until at least 40 pounds AND at least 4 years old, preferably longer. How much longer often depends on the maturity of the child.

Also keep in mind that although there are no guarantees when it comes to crash protection, the rate of child deaths in motor vehicle crashes has dropped significantly over the past several decades. This is due in part to advances in vehicle design and technology, and also due to continuing innovations in child restraint systems. Properly using child restraints according to best practice gives your child a huge advantage.