Drone observations on highways offer exceptional insights into spatio-temporal microscopic traffic events. In dense and congested traffic conditions, the analysis of lane-changing behaviors across different highways yields significant insights into driver behavior. This study analyzes lane-changing maneuvers and associated time gaps using high-resolution drone data from highways in Germany, China and the United States. The approach defines the criticality of the vehicle maneuvers in the different traffic phases as defined in Kerner’s three phase traffic theory. By assessing the safety of over 10,000 lane changes, the findings highlight the elevated risks associated with overtaking and passing maneuvers. A model is proposed to equally redistribute time gaps during lane-changing maneuvers, to systematically reduce the risks both the lane-changing and all surrounding vehicles. The results indicate around 40 % of cars maintain a time gap smaller than 1.8 s, while only 32 % of lane changes are executed as safe maneuvers. A comparison of the time gap ratio between the leading and following vehicle during lane changes reveals that, in synchronized flow, drivers tend to accept smaller time gaps ahead while maintaining larger time gaps behind, shifting the risk predominantly to the lane changing vehicle. By incorporating the proposed hypothetical model for a lane-change assistance system, the proportion of lane changes classified as risk-free could be nearly doubled to 62%.
Zürn et al. (Thu,) studied this question.