ERP2 on-board units will be mandatory for all Singapore-registered vehicles as the country fully switches to the ERP2 system from Jan 1, 2027. SINGAPORE: The number of cars allowed on Singapore roads may grow in future as the country moves closer to completing the transition to the ERP2 system next year , said Acting Transport Minister Jeffrey Siow on Wednesday (Feb 4). Singapore has been reducing its vehicle growth rate over the years, with the rate kept at zero since February 2018 for all