There are numerous traditions and superstitions in Turkey, and as in any culture, they vary from area to area and from generation to generation. Some traditions continue to be common, others are practiced by the older generations and others have become folklore.
One interesting tradition is throwing a cup of water after a car that is starting out on a long journey. This tradition is still commonly practiced and loosely translates into "go as easily as water". Or, more simply, "safe trip!".