The CDGVAL is a free, automatic metro that allows you to easily move inside the Paris CDG airport, thanks to the transfer service between certain car parks and the terminals. It serves the three terminals at Roissy airport:
It takes less than 10 minutes to connect terminal 1 to terminal 2, the last stop of the metro. The CDGVAL operates every day from 4 a.m. to 1 a.m. Outside these hours, some shuttles allow the connection, you just need to follow the directions on site. The CDGVAL circulates every 4 minutes approximately.
Outside these hours, shuttles allow you to make connections, follow the directions on site.