Analysis of the Effect of Variable Lateral Gap Maintaining Behavior of Vehicles on Traffic Flow Modeling

Vehicular interaction between different types of vehicles, in both the lateral and longitudinal directions, significantly affects the heterogeneous traffic flow modeling. From the field data it has been observed that the drivers vary gaps based on the changing traffic conditions. This variable gap maintaining behavior has been characterized using macroscopic traffic characteristic called area occupancy. Variable gaps are explained through effective vehicle width and it is found to be influenced by various factors. In this study, variable gap maintaining behavior is modeled using the concept of cellular automata (CA), with the help of a modified cell structure. Cell width in the modified cell structure has been varied corresponding to the observed variation in the effective vehicle width. It was found that the results obtained from the model incorporated with the variable gap maintaining behavior are significantly different from that of the uniform-cell-width based CA model. The effect is more significant for urban traffic conditions due to the presence of two-wheelers and three-wheelers.