Brothers Kyle and James Smith from the Vale of Glamorgan were both travelling in the same car which crashed in 2005.
Kyle was 16, not wearing a seatbelt, thrown from the vehicle and died.
James was 15, wearing a seatbelt and survived.
Their mother Angie Smith says she has "no doubt" that she would have lost both boys, had James not been wearing a seatbelt.
This year’s campaign is backed by Angie Smith, whose sixteen year old son Kyle was killed in a car crash in 2005. He was not wearing a seatbelt.
– ANGIE SMITH, CAMPAIGNER
The devastation in the years after is far worse than the initial shock that someone’s been killed. It totally takes over your life, to the point where you can’t move forward from that date.
“Kyle’s death was avoidable, and I can never alter that but I do hope that through education and continued re-enforcing of the rules we can reduce road deaths."