A Review of Road Capacity Estimation Methods and Finding the Appropriate Method Based on Iran’s condition

Road capacity is known as the intrinsic part of traffic management. The estimation of capacity is considered for several years and so many investigations have been done in this field. Therefore, some methods have found and categorized in 2 groups: direct empirical method and indirect empirical method. Direct empirical method is based on observations, while with the aim of indirect empirical method the capacity is estimated based on previous studies and models. On the other hand, it is impossible to find a deterministic value for capacity due to various driving behavioral and environmental factors. So, capacity is defined as stochastic function. In this paper various methods of capacity estimation defined and compared with each other according to Iran’s exclusive conditions like data availability. Complex mathematical procedure besides the degree of validity of each method’s result is considered as well. Finally, best method can be taken into account based on various features of study.