Car Seats

Carrying children and infants safely in the car

Published: 09/17/2021

Car seats, booster seats and why your teenager can probably legally, sit in the front passenger seat

As we all get used to the back-to-school run again and the ferrying of children to GAA matches, dancing classes and all the events that make up their enviable social lives, we might rethink travelling safely with children in the car. Not just your own, but the one lost lamb left behind after the match and the tag-along best friend, we might be tempted to squeeze in. Car seats and child -restraint systems are a necessary and legal part of bringing the kids in the car. It’s a bit different than our grandparents time, who stuffed the car high to the ceiling with excited little people for a day trip to the lake or the sea. These days on our busier roads and with safer car seat options, children travel safely and comfortably with no arguments or annoying kicks in the drivers back. Ah Ok, the last two cannot be guaranteed, but safety is, quite rightfully, a priority. Here is a quick guide to car seats, boosters and why your gangly teenager can legally sit in the front passenger seat.

What the law says

It’s all about size. Children under 150cms or 4ft 11 inches in height and under 36kg or 79lbs must use a child restraint system, or a CRS, that is suitable for their height and weight while travelling in a vehicle. (Taxis are exempt from this!) A CRS can be a child car seat or a booster seat/cushion. The seat must conform to UN and ECE regulations 44-03, 44-04 or a later version of this. It can also be a new i-size or Regulation 129. It must be the correct one for the child’s size and it must be fitted correctly. If you are taking young children in the car with you, they need to be suitably strapped into the correct seat for them.

Types of car seats

The function of the fitted child restraint system or car seat is quite simple. It prevents the smaller travelling companions from being thrown about inside the vehicle. In the event of a collision or crash, they are designed to absorb some of the impact force. 

When choosing a car seat, it is the weight of the child, rather than age that determines what type of seat you need. A reasonable guide to age, relevant to weight,  is that the high back booster which serves a child weighing 36kg is generally for a child of about 7-8yrs old. Weight categories are often called ‘groups’ by manufacturers and retailers. Below is a guide to the four main child car seat groups 0, 1, 2 and 3. However, some child restraints systems can be adapted and adjusted as the child grows. This is why a restraint system can appear in more than one group. The high back Group booster seat may have the option of becoming a booster cushion when the child reaches 22kgs (48lbs).  

Group 0 Rearward facing baby seat Birth - 10kgs (22lbs)
Group 0+ Rearward facing baby seat Birth - 13kgs (29lbs)
Group 1 Rearward or forward facing baby seat 9 - 18kgs (20 - 40lbs)
Group 1, 2, 3 High back booster seat with removable harness 9 - 36kgs (20 - 79lbs)
Group 2 High back booster seat without harness 15 - 25kgs (33 - 55lbs)
Group 2, 3 High back booster seat without harness 15 - 36kgs (33 - 79 lbs)
Group 3 Booster Cushion 22 - 36 kgs (28 - 79lbs)


RSA Guidelines

Front Seat - can a child sit up front?

There is no law against children sitting in the front seat, as long as they are using the right child restraint for their height and weight. Rear-facing child car seats must not be used in passenger seats protected by an active frontal airbag. An airbag which deploys in front of a rearward-facing child car seat can cause serious injury or even death if there is a collision. It is, in fact, illegal to use a rearward-facing child car seat in a passenger seat protected by an airbag. A front facing car seat can be used in the front seat although it is always preferable and advisable to put the wee ones in the back seat.

Can a teenager sit in the front passenger seat? Legally yes. If the teen weighs over 36 kg and is over 4ft 11 inches in height, they can safely sit in the front buckled in with the adult belt. However, you are legally responsible for the welfare of your passengers under 17yrs of age and the safest place, is suitably restrained in the back seat. So, while it is not against the law, it may be best to let them know that calling ‘Shotgun’ at the top of their voice won’t always cut it and safety must come first. 


An ISOFIX is the international standard of built-in attachment points in a car where you can fit a child seat. The benefit of a built in ISOFIX point system is that it greatly reduces the risk of fitting a seat incorrectly. Many new vehicles have ISOFIX points built in when they are manufactured, and child seat manufacturers are more commonly producing child seats that suit the ISOFIX system. If your car doesn’t have one, it can be fitted retrospectively. The disadvantage for some, is that an ISOFIX car seat can only be moved to a car with the same system, making it difficult to swop over from car to car. But the ISOFIX is ultimately safer, especially when we consider that 4 out of 5 car seats are not correctly fitted.

i-size- Regulation 129

An i-Size seat allows your child to stay rear-facing for up to 15 months in a rearward-facing baby seat. They can be fitted to most ISOFIX systems. The categorisation of these seats is based on height and size rather than height and weight. i-Size is a European standard – Regulation 129 – The key benefits of i-Size-standard seats are that they can be fitted to most ISOFIX system, and they provide increased support for the child’s head and neck. They also provide better side-impact protection in the event of collisions.

Fitting a seat

It is really worrying to know that so many child car seats are not fitted correctly. The most important thing to do before you fit any child car seat is to read the instructions. If you don’t have them, or find them hard to follow, there will probably be a video online to assist you. The seatbelt must pass through all the required seatbelt-routing guides (red or blue) according to the manufacturer’s instructions. Remember, some guides will need to be adapted, depending on what side of the car the seat is being fitted on. Surveys have consistently shown that as many the high number of incorrectly fitted seats are down to a few repeating issues. A safety belt not routed through the car seat properly or having too much slack, causing it to be very loosen the child. So called, ‘Buckle Crunch’ which is when the buckle is resting against the frame of the seat and making it easy to open. Sometimes, the wrong car set is purchased or an old one is used long after the child has outgrown it. This is not something you want to cut corners on.   

For comfort and ease, it is useful to choose a retailer who can fit child car seats for you, or at least show you how to fit it correctly yourself. Make sure the instruction manual is with your car seat when you purchase. The Road Safety Authority have introduced ‘Check it Fits’ in response to the frightening statistics on badly fitted car seats. It is a full-time, nationwide, free expert service which aims to put parents’, grandparents’, and guardians’ minds at ease that their child’s car seat is safely and securely fitted in their car. The service is quick. It’s easy. It’s free and it is usually travels round the county, though Covid -19 restrictions may have disrupted this service. Check the website for details.

Keeping the kiddies safe and buckled in properly becomes second nature, once you have the correct fitted seat for your child, your car and yourself. From all of us here at Peter Hanley Motors, as always, Safe driving!

Peter Hanley Motors is a registered
member of The Society of the Irish
Motor Industry

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