Analysis of Two-Wheeler Characteristics at Signalised Intersection under Mixed Traffic Conditions: A Case Study of Tiruchirappalli City

Two-wheelers have a substantial share of almost 40% to 50% of the total traffic mix at signalized intersections in India. Two-wheelers riding pattern is stochastic without any lane discipline or turning movement discipline at signalized intersections in Indian traffic conditions, which influences the safety and the overall traffic flow characteristics, subsequently influencing the operational efficiency of the signalized intersections. Modelling of two-wheelers' behavior and movement are essential due to their predominant role in traffic management strategies, safety evaluation, and microscopic traffic simulations. The main aim of this study is to investigate and analyze the potential influence of the varying proportion of two-wheeler composition on the passenger car unit (PCU) of each class of vehicle at signalized intersections based on intersection clearance time of the vehicles as a measuring unit. Therefore, a highly saturated signalized intersection is chosen in Tiruchirappalli City, India, as a study site, and data is collected using video cameras during the peak hours of traffic flow. The effect of the varying proportion of twowheelers and their turning movement in the left, straight, and right directions on PCU, is analyzed by building microscopic traffic simulation models with the field data. After simulating the microscopic models, the results indicated that with the increase in the proportion of twowheelers composition, the PCU values of two-wheelers and three-wheelers were observed to decrease due to their lower intersection clearance time and area. On the other hand, with the increase in the proportion of two-wheelers, the PCU values of other classes of vehicles like big cars, light commercial vehicles, buses, and trucks were observed to increase due to their higher intersection clearance time and area. Hence it can be inferred that the incremental proportion of two-wheeler composition at signalized intersections has a significant influence on the PCU values of other classes of vehicles.