The legal nature of various types of parking lot ́s contracts in Iranian and American law

The main purpose of this research is determining the nature of the relationship between driver and vehicle operator. In this article, we want to answer some questions such as: What is the nature of the relationship between driver and operator at the different types of parking lots? Whether the exclusion clause in parking's bill is valid or not? And etc.
Based on the type of parking, the nature of this legal relation is different in Iran and the American law. Some jurists believe that exclusion clause is valid and some of them believe it is invalid.