The car-free day is a day on which the use of automobiles and other motor vehicles is to be restricted. In the 1950s and 1970s, car-free days were ordered by the authorities because of a shortage of oil supplies. More recently, the car-free day is seen as an action day combined with the demand for a traffic turnaround, which is initiated and supported by various organizations (e.g. environmental associations and churches). It takes place annually on September 22nd.