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It is basically possible to hitchhike from everyplace, just keep a single rule of thumb in mind: The faster the cars the more space for the cars to stop is needed.

This is the case that the drivers consider as well. Few drivers stop unless it is safe for them. Some do, but you shouldn't count on them, as they are the minority. Therefore consider the safety of the driver as well, you don't want to involve them in an accident if they can't pull over safely. Make sure to not stand on the way, the driver will usually make its decision to stop or not while he sees you at a distance and will get ready to pull over just next to you or right behind you. If you stand too much on the way (of the normal pulling aside triangle) you will make it complicated for him and he might change his mind. So one good option is to 'make sure' that your body language point out the area he would pull over in total comfort.