SuSTAInX - Supporting Successful Transition to Adult belts In Cars: examining effectiveness of eXisting tools


  • Optimal crash protection requires the most appropriate restraint for a child’s size. For children ≥7 years of age, parents can choose whether they use seat belts or a booster seat. However, there is confusion about when children can safely use seat belts. The result is that many children >7 years inappropriately use seat belts, increasing risk of injury in a crash. 
  • There is existing information and advice aimed at helping parents to decide whether it is safe for their child to use an adult seat belt, however, they have not been tested for effectiveness.


  • The overall aim of this study is to explore the information that parents need in order to make safe and correct decisions when it comes to restraining children using adult seat belts while travelling in a car.
  • The data that we collect from this study will help us to develop easy-to-understand information resources and materials to support parents and help to reduce the level of incorrect use of adult seat belts, and thereby reduce the risk of injury to children in the event of a crash.

Eligibility Criteria

The research study is looking to recruit people who meet the following criteria:

  • Over 18 years of age.
  • Parents (or primary carers) of children aged 7-12 years.
  • Read English well enough to understand the information in the Participant Information Statement (on this page).
  • Licenced driver of own car.
  • Travel in your car with your child at least weekly.


  • If you decide to participate, you and your child will be asked to attend our lab (in Randwick or Bass Hill, NSW) at a time that works for you.
  • The lab visit activities will take 60-90 minutes. You will be reimbursed with a $25 GiftPay voucher for your time.
  • At the lab, we will ask you to observe your child in three different seating conditions and decide whether your child is appropriately restrained when using an adult seat belt in each condition.
  • Parents will be asked to “think out loud” as they assess the different seating conditions. This will be observed and recorded for later analysis.

Potential Impact

  • This will be the first study to examine information needed and behavioral targets to influence parental decision about transitioning to adult belts, building upon previous work about instructional messaging for child car seat installation.
  • This study will add new knowledge about how to effectively help parents make accurate booster to adult seat belt transition decisions, and aid in the development of new tools supporting parental decisions for increasing correct transition.

Fast Facts

  • Road trauma is a leading cause of child mortality and morbidity in Australia, costing the health system over $500 million per annum.
  • There is a ~50% error rate when considering installation and use of restraints among parents.
  • Many children over 7 years of age in Australia are moved from using a booster seat to using a seat belt inappropriately, which increases the risk of serious injury.

Please refer to the Participant Information Statement and Consent Form on this page.

Register your interest