The definition of car-sharing presented here and the quality standards and requirements discussed can provide guidelines both for the establishment of car-sharing administered by oneself and for the purchase of car-sharing services. To ensure that the car-sharing being established is effective, it is important to bear in mind what distinguishes such a scheme from traditional car-rental services, namely the ready access to vehicles, in terms of where these are placed and how keys are managed, and of its being possible to book cars for short periods of time. For such a system to be as effective as possible, it is.