Filtering is not only not illegal in France, its practically compulsory.
Driver will pull over to let you by and its discourteous not to oblige.
This follows the general axiom in France that anything not explicity permitted is prohibited and everything permitted is compulsory (OK, I exaggerate to make a point
)
In contrast in the despicable laisse-faire world of the Anglo-Saxon where everything is permitted unless it is specifically forbidden.

Driver will pull over to let you by and its discourteous not to oblige.
This follows the general axiom in France that anything not explicity permitted is prohibited and everything permitted is compulsory (OK, I exaggerate to make a point
)In contrast in the despicable laisse-faire world of the Anglo-Saxon where everything is permitted unless it is specifically forbidden.
