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Vehicle platoons were recently proposed to reduce energy consumption and emissions. However, the majority of platooning studies have focused on pure connected automated vehicle (CAV) environments with limited insights into energy consumption and emissions. This paper quantifies fuel consumption and emissions by studying the microscopic movements of CAVs and human driving vehicles (HDVs) in mixed traffic flows. With an extended cellular automaton model, a four-lane mixed traffic flow of CAVs and HDVs is investigated in detail. The results have shown that ad hoc platoon formation can lead to frequent acceleration and lane changing, resulting in more fuel consumption and emission. With a dedicated CAV lane (DCL) strategy, the interference of CAVs and HDVs is greatly reduced, thereby improving the fuel economy and emission reduction. The findings can benefit the organization of vehicle platoons in the persisting mixed traffic flow environment. [ABSTRACT FROM AUTHOR]

In urban traffic systems, alleviating traffic congestion originated from left-turn/U-turn lanes at highly demanded intersections plays an important role in enhancing the traffic efficiency. For a typical intersection, the layout with double left-turn (DLT) lanes is a relatively common geometric feature. However, the effect of DLT scheme on the performance of the entire traffic system is not clear. This paper compares the performance of urban traffic system with different lane function schemes with extended cellular automaton (CA) model considering the car-following, lane-changing, intersection-traversing and route-choice behavior of vehicles. Using the flow-density relation, three macroscopic parameters (average trip completion rate, average traffic flow and average velocity) are examined to evaluate the system performance. With the wide application of DLT scheme, the vehicles can be distributed more evenly among the lanes. As a result, the traffic flow and the trip completion rate will be higher, especially at high density. Case studies of realistic Hefei city network and Sioux Falls networks are also carried out. The results show that the performance of traffic network will be better if more intersections adopt the DLT scheme. [ABSTRACT FROM AUTHOR]

Connected Autonomous Vehicle (CAV) platoon was recently proposed to improve road utilization and reduce fuel consumption. However, the mixed traffic flow of CAVs and human-driven vehicles (HDVs) will exist on the road for a long time; thus, the organization of CAVs needs to be reconsidered from the aspects of the platoon forming strategy. In this paper, a novel cooperative platoon forming (CPF) strategy is proposed to enhance the formation of CAV platoons in mixed traffic flows. A four-lane cellular automaton traffic modeling framework is constructed to simulate the interaction between CAVs and HDVs. Numerical results show that the CPF strategy is effective in enabling CAVs to be assembled into platoons. The increase in the CAV penetration rate can effectively alleviate traffic congestion and improve traffic capacity, thereby improving traffic flow and fuel economy. The findings may help improve the management of vehicle platoons. • A novel cooperative platoon formation strategy is proposed to promote CAV platooning. • A four-lane cellular automaton traffic model is constructed dealing with CAVs and HDVs. • The strategy effectively improves traffic performance and reduces fuel consumption. [ABSTRACT FROM AUTHOR]