top of page

What is the 'Two Hour Rule' for Baby and Car Seats?

Updated: Jun 4, 2022

The 'Two Hour Rule' is an established safety recommendation endorsed by safety experts and car seat manufacturers that suggests babies shouldn’t sit in a car seat for more than 2 hours at a time.

There are two main reasons for this:

  1. Too much time causes a strain from the curved seating position on the baby’s still-developing spine.

  2. While they are little, the position can cause restricted air-flow to the baby’s lungs. The chance of this can increase if a baby falls asleep with their head flopped forward.

This applies to anytime Baby is in the car seat. It doesn't matter if Baby is in a stroller, in the car, on an airplane, or just at home.

Photo by Kampus Production from Pexels

The Research

A preliminary study conducted at Swindon’s Great Western Hospital in the UK was done by the University of Southampton and the University of Bristoll and commissioned by the Lullaby Trust.

The study looked at 40 (21 premature babies and 19 full term) babies. They were strapped into a car seat and the test included a simulated 30 mph journey, where the babies were sitting at a 40 degree angle (as they would be in most car seats in a car).

When the babies sat in the car seat for 30 minutes, their heart and breathing rate increased, and their blood oxygen levels were lower compared with lying flat in a cot. This happened when the babies were both stationary in the car seat and ‘moving’ in the car simulator. These effects were more marked with premature babies but still seen with every single full term baby.

This has lead car seat safety experts to make the 'Two Hour Rule' a very real recommendation although even more related studies should still be done.

The report itself states that because of the small nature of the study “we cannot be certain of the clinical significance or potential risks”. It is quite unethical to take the study too far. So the researchers themselves aren’t clear whether the lower levels of oxygen create a serious risk or mean that your baby could be at risk of stopping breathing.

They just don’t know how dangerous or not lower levels of oxygen are for your baby. But, this is an important study. It’s raised some questions and what all the experts are saying is that more research is needed with a much bigger sample of babies.

Still, the key advice right now, according to the experts – even those behind the study – is that currently, the safest way for a baby to travel in a car is in a car seat. Period.

So if your baby has to travel in a car, you should still use a car seat. It’s also required by law.

The Royal Society for the Prevention of Accidents advises parents to take a 15 minutes break every two hours to relieve their own fatigue and give their baby a break from their car seat – something which was echoed by Francine Bates, chief executive of the Lullaby Trust, who said:

“We recommend that parents also avoid driving long distances without a break. However, avoiding the risk of injury due to a road traffic accident is paramount and fitted car seats should always be used to transport babies and toddlers. It is clear that further research is needed to explore what more we can do to ensure babies are safe and comfortable when traveling in a car seat and we will be convening an urgent summit of leading child car seat manufacturers to take this forward in the autumn.”

However, it has to be said that one of the researchers, Professor Peter Fleming, is issuing stronger advice. In an interview with the BBC, Professor Fleming stated that newborn babies could be at risk of suffocating when taken on long car journeys, and that there should be separate car seat safety advice for very young babies. His stance was “If you can avoid a journey, it’s probably better to do so. Or restrict it to say 30 minutes or so.”

Photo by Kampus Production from Pexels

What does this mean for you?

Now, I certainly know that the thought of stopping every 2 hours on a 12 hour road trip can seem ridiculous. But I would argue that its massively important to do especially if baby is under the age of 6 months when they are still developing neck and head strength.

As baby gets older you can go for longer stretches but even a 3-4 hour time span between stops should be the maximum for children under two.

And if baby is sleeping and is breathing normally, by all means keep driving. But once they wake up you should look for a place to stop.

What can you do to travel safely?

There are things that you can do today to make sure that your baby, even a newborn, travels as safely as possible in a car seat.

1. Don’t use a car seat as a general place for your baby to sleep in. A car seat is for transporting your baby in a car. I know that it’s a pain, but once you are home you should transfer them to a safe sleeping surface.

2. If you’re using a car seat in the first four weeks of your baby’s life, avoid using it for longer than 30 minutes, either in a car or as a combined period of time as part of a travel system (stroller and carseat combo).

3. If it’s unavoidable that your newborn has to travel in a car seat for longer than 30 minutes in those first four weeks, have an adult sitting in the back of the car with your baby to regularly check on them.

4. Know of the Two Hour Rule and be sure to follow it. Take the breaks from the car seat. Get baby out and let them stretch.

5. Don’t be tempted to keep your baby for prolonged periods in a car seat when using it as part of a travel system. “The largest issue recognised for the ‘over use’ of car seats,” warns the Baby Products Association (BPA), “is when they are not used purely as a safety product in the car but when used combined with a stroller to form what is often called a ‘travel system’.”

Alternatives to the Car Seat:

Stroller - Are you finding that you will be using your stroller for more than two hours? Depending on how big the baby is, there are other options you can use instead.

Many stroller brands offer a pram/bassinet option, sometimes even included with the original stroller purchase. This is great for smaller babies. They can lay flat on their back for however long and it can even create a nice nap environment for Baby while you are out and about.

If Baby is a bit older and wants to sit up, you can use the toddler seat. Some brands have a reversible seat so it can face forwards or towards you. Some also have an infant insert that help smaller babies fit comfortably and safely into the typically longer toddler seat although this should be used only if baby is remaining in an elongated and flat position that doesn't put a strain on Baby's spine.

At home - First and foremost, it is important to understand why you are putting baby there as opposed to somewhere else. Do they sleep better in a moving or rocking car seat? Maybe you can try a swing or bouncer that keeps Baby strapped in but lying flat. You could also try a rocking bassinet.

If for another reason, try to see if there are other options to keep Baby out of the car seat for extended periods of time.


Click Below to Download SafeKids.Org's Car Seat Safety Checklist

Download PDF • 1.24MB


bottom of page