# A Systematic Literature Review of Autonomous and Connected Vehicles in Traffic Management
## 3 Research Analysis
### Traffic Management Methodologies Consisiting of Primary Goals
#### 3.2.1 Efficiency  
Numerous techniques have been used to enhance the efficiency of AVs and CVs in junctions, roundabouts, and interchanges. Different studies considered a variety of subgoals, including lowering traffic delays, increasing junction flow, and lowering the chance of congestion. The study examined the suggested strategies for improving conflict zones' effectiveness. One paper [91] proposed a time-independent trajectory optimization strategy for connected and autonomous vehicles under reservation-based junction control to reduce the evacuation time of a group of vehicles. The method locates the best answer in terms of intersection efficiency. Similarly, the authors in [51] used a dynamic programming technique and the heuristic least extra time (SET). The effectiveness of the heritable, branch-and-bound algorithms, heuristic, and dynamic programming was compared by [PERSON] et al. to that of the adaptive control and conventional stable-cycle-time systems. The findings demonstrated that the suggested approach could speed up evacuation times and shorten typical queues and vehicle wait times. Additionally, ref. [52] proposed a temporal delay Petri net-based (TdPN) control strategy to create a cooperative vehicle infrastructure system to enhance the intersection's performance. The results show that when the traffic flow rate exceeds 1200 automobiles per hour, the TdPN approach beats conventional signal management systems associated with the delay, average queue length, average stop time, and average speed. Furthermore, ref. [24] provided an Autonomous Intersection Management technique based on an ant colony technique and discrete optimization technique to address real-time control issues with many vehicles and lanes considering an individual vehicle and real-time junction control. The suggested approach performs better than the current methods in terms of throughput, mean queue length, evacuation time, and mean vehicle delay. Similarly, ref. [53] suggested a game-theory-based approach for managing the Cooperative Adaptive Cruise Control (CACC) system-equipped autonomous vehicle movements at uncontrolled crossings. This research project aims to create an algorithm that can use connected and autonomous vehicles' capabilities in the future to replace the conventional state-of-the-art control systems at junctions (e.g., stop signs, traffic signals, etc.). The suggested approach  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Reference**} & \multicolumn{4}{c}{**Driving Objectives**} & \multirow{2}{*}{**Adopted**} \\  & **Efficiency** & **Safety** & **Ecology** & **Passenger** \\  & & & **Comfort** & **Methodology** \\ \hline
[11; 24] & ✓ & ✗ & ✗ & ✗ & Hybrid \\
[25] & ✗ & ✓ & ✗ & ✗ & Hybrid \\
[26; 27; 28; 29; 30; 31; 32] & ✓ & ✗ & ✗ & Hybrid \\
[33] & ✓ & ✗ & ✓ & ✗ & Hybrid \\
[34; 35  
is practical for use in real-time applications and was inspired by the chicken game. To provide their instantaneous speeds and positions, it is assumed that vehicles can interact with a central agent at the intersection. One paper [83] proposed PriorFIFO, a reservation-oriented priority scheduling approach, as a solution to the autonomous passing-through issue. Moreover, ref. [84] developed a unique reservation-based scheduling processor called csPrior-FIFO to prototype and build the traffic entities, such as service-oriented heterogeneous vehicles, centralized scheduler I-Agent, and their uniform behavior states. In terms of scheduling performance and latency, both approaches beat the FCFS technique. A time-sensitive programming approach was also suggested in [85] to address the RTD issue. Under situations of high input flow, it outperforms AIM. Moreover, ref. [86] presented Batch-Light, an adaptive smart intersection control approach for AVs, which is a reservation-based control method. They employed a greedy-based conflict matrix decision algorithm to enhance the likelihood of a reservation with fairness.