In the USA, traffic-related injuries are responsible for over 33 000 deaths each year 1 and are the leading cause of death for individuals aged 1-24 years.2 Traffic-related injuries also take a substantial economic toll, accounting for over $99 billion annually in medical costs and associated productivity losses. 3 Globally, >1.3 million people are killed each year by traffic-related injuries, and an additional 78.2 million sustain nonfatal injuries warranting medical care.