check their bags and take an internal flight to a French airport without having to pass through Swiss territory;
For some airlines flying to destinations other than France, check in and go to the international transit area.
make your way easily to the nearby areas of France (Pays de Gex, Divonne-les-Bains, Bellegarde, French Jura Mountains, the departments of Ain, Jura, etc.).
rent a car from a French agency.