A Study on Passing - Overtaking Characteristics and Level of Service of Heterogeneous Traffic Flow

Abstract: A model of passing-overtaking maneuvers in terms of total traffic volume and percent of rickshaws is presented in this paper; the model is applicable to undivided urban streets with relatively high proportion of rickshaws. Effects of nonmotorized rickshaws on passing-overtaking are also presented. The results suggest that rickshaws have an adverse effect on the passing-overtaking maneuvers. This paper has also attempted to provide a classification of Level of Service (LOS) for heterogeneous traffic composition in urban areas. In this study LOS are firstly defined in six standard groups, such as levels A, B, C, D, E, and F. The operating characteristics considered to define the level of service are: total number of passings -over takings (no/hr/20m) and average speed of passenger cars (km/hr). Based on the observed data the levels of service are classified into four groups from the road users point of view, namely LOS I (Free-flow condition), LOS II (Partial-constraint flow condition), LOS III (Constraint flow condition), and LOS IV (Congested-flow condition). Level of service classification evolved in this study will help to identify deficiencies of an urban streets system and to plan for alternative improvement measures to attain a desired level of service.