Track-laying begins for Paris tram-train line T4 extension March 28, 2017 | Europe News Track-laying has begun for the 6.5-km extension of the Paris tram-train line, T4. The extension will connect Livry-Gargan and Clichy-sous-Bois to Montfermeil. It is scheduled to open by end-2019.... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password