# A Systematic Literature Review of Autonomous and Connected Vehicles in Traffic Management
## 3 Research Analysis
### Traffic Management Methodologies Consisiting of Primary Goals
#### 3.2.6 Efficiency, Safety, and Ecology  
The papers that jointly addressed efficiency, safety, and ecology are included in this section. At an unsignalized junction, ref. [71] suggested the vehicle-intersection coordination system (VICS), based on the MPC architecture, which aims to reduce fuel consumption and increase traffic efficiency. Compared to a traditional signalized intersection, the proposed technique improved intersection performance variables, such as vehicle stop times, traffic flows, fuel consumption, and intersection capacity. Additionally, by splitting the junction into three primary communication zones, ref. [112] presented a novel intersection model based on the multi-agent reservation technique to reduce overall delays and power loss and increase accident detection. This tactic decreased both the overall delay time and power loss. Additionally, it reduces energy waste, prevents crashes, and efficiently traverses intersections. A multi-objective evolutionary algorithm (MOEA) was also suggested by [113] to find safe routes for AVs in a junction by safely and efficiently routing vehicles. The simulation results show that the strategy works well in low-traffic situations. To obtain nearly optimum CAV paths free of junction conflicts, ref. [114] suggested signal-head-free intersection control logic (SICL). The proposed approach employs stochastic lookahead to minimize intersection throughput, reduce travel time, eliminate pauses, and minimize fuel consumption. Comparing the proposed method to signal control approaches, travel time may be cut by 59.4-83.7% depending on the kind of traffic. To reduce travel time, energy use, and fuel consumption while maximizing throughput at an unsignalized junction with guaranteed safety, ref. [34] suggested a decentralized energy-optimal control system. Comparing the recommended method to the current traffic signal management systems, it is possible to achieve fuel savings of 47% and travel time reductions of 31%. Platoon-based autonomous intersection management (PAIM), proposed by [72] to reduce interruption and inconsistency at the junction, is a centralized platoon-based controller based on reservation policy and cost function. The suggested strategy works better than traffic signals regarding delay and fuel usage. To reduce accidents and enhance traffic at the junction, ref. [73] proposed a decentralized approach called the cooperative intersection control (CIC) technique. The simulation results show that the suggested technique performs better throughput and latency than the conventional traffic light. A novel junction management method considering the non-linear vehicle dynamic model and meteorological circumstances was suggested by [115]. By up to 80.0%, 40.0%, and 42.5%, respectively, the proposed technique decreased delay, CO\({}_{2}\) emission, and fuel use based on the simulation's findings. To find the best answers, the proposed approach may have a high computing cost. Research [116] proposed a strategy based on cooperationbetween AVs and the roadside unit to increase junction effectiveness and reduce fuel usage. The suggested approach performs better than both traditional fixed switching and cutting-edge algorithms. Another study [35] presented a cooperative approach to regulate the speed of AVs at the intersection and optimize traffic signals. According to the simulation findings, when traffic demand is between 800 and 3200 vehicles per hour, the suggested solution results in less fuel usage and travel time than actuated signal control. Codrive, a cooperative speed advisory system, was suggested by [74] to reduce fuel usage at signalized junctions. According to the simulation results, the fuel consumption is lower compared to the Green Drive by 7.9 to 38.2%. Additionally, ref. [75] suggested an approach for increased safety, decreased fuel use, and less transportation congestion and pollution. They investigated the effects of achieving a smooth traffic flow on roundabouts by wirelessly connecting vehicles and coordinating them as efficiently as possible.