The Île de France  is the compact region immediately surrounding the capital of France, Paris. As such, the region includes the now far-flung suburbs of the Paris metropolis, together with several large surrounding towns that form part of the larger conurbanation. All is not urban sprawl, however: the region is also known for its natural beauties, in the form of parks, forests and river lands.
There are many cycle lanes on routes into Paris, but be careful as you also share the road with motorbikes and cars which can be inconsiderate.
There are several free Autoroutes and 4 lane roads for getting round Île-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.
The speed limit is 110 km/h.
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 miles) 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.
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 AM to 1.30 AM, and smoking is not allowed whilst in stations or on the trains.