Use ViaMichelin Route Planner for driving in northern France?

I don't drive in Europe, but I know that if you zoom way in on ViaMichelin maps, you will find the most scenic routes outlined in green. You can also click on the "Options" button and choose "Discovery" under "My Route Options". Mind you, I have no idea what "Discovery" means in this context, but it sounds interesting.

The "discovery" option will try to maximize the use of green-highlighted roads.
Regarding those "green" roads, on https://www.viamichelin.com/web/Maps, if you zoom in enough, you will see a very discreet "Michelin Map" option appear on the right (below the +/- zoom buttons). Click on it, a new window will pop up with a scan of Michelin paper maps. Usually 5-10 years out of date, but still very helpful to plan scenic routes.

For your specific journeys:

• CDG to Sourdeval is fairly long. The N12 via Dreux, then due west through l'Aigle, Argentan, Flers is probably the best route (I used it to go to Granville in the past). Much more scenic than the slightly faster A13 motorway via Caen, and free. if you have time, the Orne valley north of Flers is very pretty.

• Sourdeval to Saunay: try to pass by Saint-Céneri and (slightly longer detour) nearby Saint-Léonard-des-Bois; the Sarthe valley is beautiful around there. Then I would just join the A28 motorway at Junction 20 for the rest of the journey - but do stop in Le Mans for a few hours if time allows! Beautiful city.

• Saunay to Lauterbrunnen: no time to dally! If you choose the Besançon-Morteau-La Chaux de Fonds-Neuchâtel route across the Jura (for me, the best compromise between ease of driving and scenery), you might have time for a quick photo stop at the Roche du Pretre overlook near Morteau.

• Lauterbrunnen to Colmar: I would go through Brienz and Brünigpass, then just take the highway via Luzern & Basel.

Acraven, thanks for the explanation! Very helpful.

Balso, Wow! This is fantastic. Thanks for all the detailed information about my routes!