Highways and Public Works

Car Seat Safety - Stage Three

This stage is a Booster seat. Your child must weigh over 22 kg (48 lb) for this stage.

Booster seats ensure proper seat belt fit by raising the child to correctly position the adult seatbelt across the bony structure of the chest and pelvis. The seatbelt system secures both the child and the booster seat into the vehicle.
Please remember that even when a booster seat is unoccupied, the seat belt assembly must be done up around the booster seat so that, in the event of a collision, it does not become a projectile.

Securing your child and booster seat properly into your vehicle

Step 1: Read your manuals

  • Ensure you have read both your vehicle manual and your booster seat manual prior to installing your car seat.
    - Your vehicle will let you know where your vehicle manufacturer recommends placing your car seat and how your vehicle seat belts maybe used with car seats.
    - Your car seat instruction manual will let you know how to use your car seat.

Step 2: Pick a seating position

  • The best location for any booster seat is in the centre back seat. However, in some vehicles and situations this is not possible.
  • Any seating position that you pick, you will need to ensure that 80% of your booster seat is supported by the vehicle seat. If this cannot be achieved you will need to find a new seating position or a different booster seat.
  • If your vehicle is equipped with air bags, click here for more information before installing your booster seat. 

Step 3: Securing your child

  • All booster seats must be used with a lap/shoulder seat belt. 
  • Place your child on the booster seat.
  • Place the lap portion of the seat belt over your child's lap and the booster seat, secure in place, and ensure that it is positioned low and snugly over the child's hips and pelvis area. 
  • Ensure that the shoulder portion of the seat belt is sitting diagonally across the middle of your child's shoulder and in front of the chest. Consult your booster seat manual if you need to adjust the shoulder belt.
  • Ensure that the midpoint of your child's ears is NOT above the back of the head rest or car seat. If it is, their booster seat can not be used and another one that is taller should be purchased.

Never place the shoulder belt under the arm or behind the back of your child. In the event of a collision, these actions could cause serious injury. For more information on collisions and car seats, visit our car seats and collisions page.

*** Note: When switching your car seat from a harness system to a booster seat, you must remove the harness system completely from your car seat.***

Further Information:

Transport Canada - Stage 3 - Booster Seats

Canada Safety Council - Stage 3 - Booster Seats


Contact Car Seat Safety Program

Government of Yukon
Department of Highways and Public Works
Box 2703 (W-17)
Whitehorse, YT Y1A 2C6

Phone: (867) 667-5832
Toll free (in Yukon): 1-800-661-0408, local 5832
Fax: (867) 667-5799
Email: road.safety@gov.yk.ca