CRITICAL HEADWAY AT UNSIGNALIZED INTERSECTIONS - LITERATURE REVIEW

: The critical headway is one of key traffic flow parameters for determining the capacity and level of service. The adoption of recommended critical headway values leads to inaccurate capacity estimation and poor investment decisions. Therefore, it is very important that the estimated values of this headway be as precise and accurate as possible in order to reflect the real behavior of drivers and real traffic conditions of a certain area or country. This paper provides a synthesis of selected studies in which the critical headway was estimated on the basis of real data collected at unsignalized intersections. The aim of this paper is to summarize the key results and conclusions related to the factors influencing the probability of accepting a headway and the most commonly used methods for its estimation. A detailed search of studies in which critical headways were analyzed revealed that no review paper on the analyzed intersections has been published so far.