The full categorisation of countries under the three-way system is to be released later A traffic light system, which will categorise countries based on risk alongside the restrictions required for travel, has been rolled out by the UK government on Friday as part of plans to lift the current restrictions on non-essential overseas travel to control the spread of COVID-19. The system, which slots countries under a red, amber and green system, will determine which set of travellers require varying degrees of hotel or home quarantine, with a stringent coronavirus testing regime in place. The full categorisation of countries under the three-way system is to be released later, expected in time for the next stage in the ease of lockdown on May 17.