Paris Metro Lines 4 and 12 extension projects delayed due to COVID-19 pandemic, France October 15, 2020 | Europe News Régie Autonome des Transport Parisiens (RATP) has announced that the opening of Paris Metro lines 4 and 12 extensions will be delayed by several months due to the implementation of measures to ... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password