''Porte d'Orléans'' is the terminal subway station of line 4. There is an entry on the ''périphérique'' ring road where lots of people are later heading South. The best place is besides the "Novotel" building or (better) opposite it at the traffic lights. Be warned, traffic here is heavy and fast moving. If you have much baggage or more than one person I would not fancy your chances here. Waiting at the petrol station or even the adjacent war memorial will not give you the best traffic.
Edit : I think that the place in front of the hotel is pretty bad. Very hard for the cars to stop there. It's better to stand before, at the red lights. I stood near the gas station at the lights, you miss all the cars not coming from inside Paris, but it's way easier for the cars to see you and to stop.
Make sure to specify with a sign specifying that you go to [[Orléans]] or [[Chartres]] (if you are heading Southwest - A10 or A11), and that the driver will leave you at least at the "péage de Saint Arnoult" or before that at "Limours-Janvry" service station. Beware, just after the "péage", the motorway separates between A10 and A11. If you are heading directly South onto the A6, have a sign (you may try "[[Lyon]]" or Fontainebleau) and make sure to be left at ''Aire de Lisses'', roughly 35 km further, a little bit after Evry (drivers to Evry are not enough for you)
. Whenever a diplomat travels between Paris and the Orly airport, he'll go through here. Which means that there will be police presence. The police don't care about you, but it is very unlikely anyone will stop while they are around. That happens often enough. They stick around for one hour.
==== Option 2: Porte d'Italie ====