Influence of the surrounding traffic characteristics on lane changing decision of heavy vehicle drivers

Lane changing manoeuvres have major impacts on traffic flows. Despite the increasing number of heavy vehicles on freeways, previous lane changing studies are predominantly associated with passenger cars. This study uses a detailed vehicle trajectory data analysis to investigate the effects of microscopic characteristics of the surrounding traffic on lane changing decision of heavy vehicle drivers. Lane changing decision can be divided into two stages: the motivation to change lanes and the selection of the target lane. To investigate the factors which influence heavy vehicle drivers' lane changing decision, 42 heavy vehicle lane changes are analysed. Heavy vehicles are classified into heavy trucks and light trucks based on their length. The results show that the speeds of the front and the rear vehicles in the current lane may motivate the heavy vehicle drivers to change lanes. Furthermore, the speed difference between the lead and the lag vehicles in both adjacent lanes has an impact on selection of the target lane. In general, different influencing traffic characteristics are observed in lane changing decision of heavy truck and light truck drivers.