Study of Vehicle Specific Speed Profiles at Merging and Diverging Sections of Toll Plaza Using UAV Data

The complexity of vehicular interactions at the toll plazas is more severe than in any other traffic facility due to the multiple decisions the driver has to make in a really short time. This creates a lot of interactions between different vehicle classes and hence hinders the smooth movement of vehicles inducing safety issues and delays. The present study investigates and quantifies longitudinal and lateral speeds at the toll plazas operating under heterogeneous and non-lane-based traffic conditions. High-quality trajectory data are developed from the traffic video recorded using two Unmanned Aerial Vehicles (UAVs) flying simultaneously upstream and downstream of the toll plaza. Distribution fitting for longitudinal speeds has also been attempted in this study. The mean longitudinal speed in the merging section is 33.13% lower than in the diverging section. The average lateral speed observed in the merging section is 1.65 km/h, whereas, in diverging section, it is 2.08 km/h, which is 26% higher. The lane changing or selection is prominent only up to 120–140 m from the toll plaza in the merging section and in a zone of 100–200 m toward the toll plaza in the diverging section. The longitudinal speeds in merging and diverging sections distinctively followed the generalized extreme value (GEV) distribution. The observation and results are expected to contribute toward the more realistic imitation of field conditions in heterogeneous traffic for simulation studies and will help in reducing delays and improving the facility's overall efficiency.