Analysis of the Lateral Gap Maintaining behavior of Vehicles in Heterogeneous Traffic Stream

In India, vehicular traffic is heterogeneous and vehicles do not follow lane discipline and can move anywhere on the available free space of the road. Lateral gaps maintained by the vehicles play major role in the passing/overtaking behavior of the following vehicles. For a detailed understanding of the lateral gap maintaining behavior huge data, covering various traffic scenarios, are required. In this study a detailed methodology for collecting the microscopic traffic data has been presented. It has been observed that the lateral clearance between two adjacent vehicles significantly vary depending on several traffic conditions. Speed of the subject vehicle, speed and type of the adjacent vehicle, and road width, were found to be significantly influencing the lateral gap. It has been found that the lateral gap maintained by vehicles, moving with similar speeds, can be modeled with normal distribution. Similarly, lognormal distribution can be used in modeling the gaps maintained by a vehicle moving with certain speed with respect to any speed of the adjacent vehicle.