By train
A network of regional trains RER takes you in and out of Paris. The RER has 256 stops in and around Paris, and runs on over 587 km 365 mi of track. There are 5 lines, A, B, C, D and E that cross Paris, connecting suburbs on opposite sides. The stations are marked with blue signs with a white RER. There is also a separate network of trains Transilien that depart from the main train stations Lyon, Est, Nord, St-Lazare, Montparnasse and La Défense.
It is usually cheaper to purchase a daily ticket than a return ticket for most journeys, but check when purchasing.
Trains run from 4.45 a.m. to 1.30 a.m. Smoking is not allowed in the stations or on the trains.
By car
There are several free Autoroutes and 4 lane roads for getting round Ãle-de-France, however on weekdays there is a lot of congestion between the hours 8 - 9:30 AM and 17:30 - 19:30 PM, and it is really not advisable to travel then. This congestion becomes a lot less worse the further away from Paris you are.