What time do metro and train starts to work? By | January 18, 2017 | in Vote Up 0 Vote Down Answered Public Public Private Questions Anonymous asked January 18, 2017 I need to fly from paris to Rome at 6.30AM on Monday from CDG airport, how can i go by metro or RER? 1 answer Vote Up 0 Vote Down Public Ben Lam ⋅ Staff ⋅ January 19, 2017 That's likely too early for RER trains to CDG. Try the night bus. #1 Please login or Register to Submit Answer Username or Email Address Password Remember Me