Even if you are using GPS on your trip, planning the route ahead on a Michelin road map is beneficial, for one specific feature: green roads.
When a road is particularly pleasant to the eye, such as having beautiful vistas and forests etc. then it gets a green line. These roads attract extra traffic seeking to admire the scenery.
Now there are big roads and smaller roads.
When in an area some of the smaller D roads have a green line the area is not especially noteworthy.
But if the Route Nationale and other big roads are green then the whole area is beautiful. They just don't color the D roads if the N road already has a green line, or the whole map would be green. But usually the uncolored D roads are even better than the colored big ones - and devoid of lines of slow moving tourists as a bonus.
So seek out the areas where the big roads have green lines and drive on the smaller uncolored roads
And avoid city centers.
You easily lose half an hour ploughing through some dusty 70.000 inhabitant town where you could have driven round in minutes. There always is a detour or one of 20 other reasons to regret being there.
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