The elimination and absorption mechanism of oscillatory motion wave based on jam-absorption driving for mixed traffic flow in intelligent connected environment

Abstract

With the emergence and development of connected and autonomous driving technologies, managing the behavior of connected autonomous vehicles (CAVs) within mixed traffic flow can mitigate traffic oscillation and enhance overall traffic performance. In recent years, the congestion absorption strategy known as jam-absorption driving (JAD) has been proposed, demonstrating efficacy in absorbing motion waves. Based on this premise, the paper addresses congestion phenomena on roadways by utilizing the real-time control system for JAD within a localized mixed traffic environment of CAVs. This system detects and locates the formation of mobile motion waves, estimates their starting and ending points, selects appropriate CAVs to serve as absorbing vehicles, and issues commands to activate them while choosing suitable control modes to facilitate the absorption of motion waves. Finally, simulations employing a stochastic car-following model are conducted to replicate experimental traffic phenomena and outcomes, testing the real-time absorption effects of varying absorption speeds on motion waves. The results indicate that the JAD system effectively eliminates both single and double motion waves observed during the experiments. In the analysis of individual motion wave, the application of the JAD system resulted in reductions in average speed, speed standard deviation, and speed variability, with speed variability decreasing by as much as 16.22 %. In terms of vehicle collision risk, compared to before the implementation of the JAD system, the platoon's TET and TIT values decreased by 15.45 % and 15.77 % respectively. Regarding energy consumption, the maximum reduction was 6.51 % at a speed of 12.5 m/s. As for emission, CO₂ emission decreased by up to 25.05 %, NO_x emission by 30.30 %, VOC_x emission by 1.63 g/km, and PM emission by 31.53 %.These findings validate that the JAD system effectively mitigates motion waves and reduces traffic oscillations by experimental data, thereby enhancing the efficiency of mixed traffic flow and improving roadway safety.