PARIS TO CDG AIRPORT BY CAR
Our advice is don't do it !!!...use another form of transport .....see here
If you really have to, to return a rental car for example, here are the driving directions to Roissy Charles de Gaulle Airport from central Paris
To get to Charles de Gaulle (CDG) Airport from Paris you can take either the A1 or A3 auto-route. These roads can be accessed from the péripérique ring road (in either direction) or directly from central Paris.
As you can see, from the périphérique to get to the A1 you have to make your way to 'Porte de la Chapelle' and for the A3 'Porte de Bagnolet'.
At Porte de la Chapelle
From within central Paris, Gare du Nord is a good point of reference as from here you can make your way north along Rue Marx Dormoy which continues as Rue de la Chapelle before eventually taking you directly onto the A1.
At Porte de Bagnolet
From central Paris a good point of reference for Porte de Bagnolet is the Pére Lachaise metro station and the cemetery itself. from there proceed along Avenue Gambetta then continue on Rue Belgrand through Place de Porte de Bagnolet and onto Avenue de la Porte de Bagnolet before crossing over the périphérique onto the A3 for the airport.
At the Airport
The GPS code for Paris Charles de Gaulle Airport is GPS: N 49° 0' 38.56'' E 2° 33' 38.92''.