What is the Gordon Rule?

Gordon's Rule of Threes: Every hour, three people on earth will die in a road traffic crash (RTC); at least 50 are seriously injured. Every day around 3,700 people around the world will die and more than 100,000 are injured or disabled - mostly vulnerable road users, i.e. pedestrians, cyclists and motorcyclists; almost half are young adults aged 15-44 years.