Methodological framework for modeling following behavior of vehicles under Indian traffic scenario

The present research work is originated with an intent of studying traffic flow characteristics on intercity. For this purpose, two expressway sections: (i) Pune-Mumbai Expressway and (ii) Ahmedabad-Vadodara Expressway were selected, as these are the best available roads in category of intercity expressways, in India. During the course of work, it was found that data may not be fully adequate to develop Measure of Effectiveness (MOEs) thresholds. Consequently, simulation-based approach is to model the traffic flow on selected study sections. With this motivation, simulation model, namely, VISSIM-9.0 was calibrated using newly developed methodology for mixed traffic conditions. In particular, driving behavior parameters were calibrated using high-quality vehicular trajectories. A well-calibrated simulation model was then applied for developing speed-flow-density fundamental diagrams, and thereby determining capacity and Level-of-Service (LoS) thresholds using density and V/C ratio. It was found that the capacity value for six-lane divided expressway (three lanes in each direction) is determined as about 7500 PCU/h/direction, which reasonably matches with the US-HCM (2010) guidelines. It is anticipated that the proposed method of calibrating vehicle-following driving behavior using high-quality trajectory data is transferable to other mixed traffic conditions.