Behavior & Development • Jun 16, 2015

Where to Place the Second Car Seat? A Simple Question that Stumped a Dad and Doctor

iStock_000021086649_Small“When we have our second baby,” my wife asked me, “Where is the safest place to put the second car seat?”

This should have been a simple question.  I am an informed dad, and I am a doctor. I have counseled many parents on car seat safety as part of my routine practice in pediatrics. But I was stumped. I had my best guess, but I didn’t know what the evidence supported. To find the answer, I reached out to a couple physician-friends, but they only had their own “best guesses.” So I did what any good doctor and husband would do: I sifted through the literature in search of an answer. Little did I know how difficult the answer would be to find.

To start my quest, I read through the AAP guidelines, but they did not specifically mention placement of multiple car seats. Then I read through a few review articles with no more success. Next, I performed a thorough search of all the recent literature on vehicle safety in pediatrics. Zilch… Finally, I stopped at the Safety Stop at St. Louis Children’s Hospital to ask for help. The answer was a resounding, “It depends…”

Here was their helpful advice:

1)      Safest place for a car seat is the middle of the backseat. Place the most vulnerable child in the middle of the back seat, if possible. In our car, we placed our infant car seat in the middle, with my toddler’s forward-facing seat on the driver’s side. This is farthest from the windows and offers the most protection. This may not work when installing two car seats in smaller cars, however.

2)      It probably doesn’t matter where you place the second car seat. The left-side and the right-side of the back seat are both appropriate positions for the second car seat. Many people have opinions on which is the safest position, but highway safety reports show that there is no statistical difference in terms of safety. (That is probably why I couldn’t find the answer in my review of the literature.) Instead, the decision should be based on other factors:

  • Type of vehicle: In some cars, two car seats will not fit side-by-side in the back seat. In these situations, it is most important to have each car seat safely installed, even if they are placed on opposite ends. Also, larger vehicles may have rear bucket seats with benches in the last row. For many parents, it is difficult to get children into and out of car seats on the rear benches. In these instances, the bucket seats may be the best choice for placement.
  • Behavior of the older child: Sometimes, older children can pose a risk to the baby. They may try to feed the baby, play too forcefully, or even hit the baby. In these situations, it may be safest to have the car seats on opposite sides.
  • Type of car seat: Rear-facing seats take up more room than forward-facing seats. For tall drivers, this may cause the car seat to become wedged behind the driver’s seat, which is not safe. In this case, the passenger-side may be a better choice.
  • Ability to safely remove children: There are a few things to consider here. First, the rear driver’s side is often in the lane of traffic, so you will be getting your child out with cars potentially buzzing past. Also, it can be difficult to get children out of the center seat. You may end up accidently bumping the older child’s seat out of alignment, requiring frequent adjustments.

Most importantly, make sure that you are following basic safety guidelines for car seats. Studies have shown that a vast majority of car seats are installed incorrectly. It doesn’t matter where you place a car seat if it is used incorrectly. Here is a previous article by Dr. Lenhardt that debunks many of the myths about car seat safety. Also, below is a reminder of the basics for car seat transitions. As always, check the specific recommendations for weight, height and installation that come with the owner’s manual for your specific car seat. Remember that each transition decreases overall safety. Moving to the next step should be a necessity, not a celebration. If you have any questions, call 314.454.KIDS (5437) to schedule an appointment at Safety Stop at St. Louis Children’s Hospital. Also, check out “Parents Central” on  for reliable car safety information.


car seat table