# Coordinated Multi-Platooning Planning for Resolving Sudden Congestion on Multi-Lane Freeways
## 2 Background and Related Work
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Lit.** & \begin{tabular}{c} **System** \\ **Architecture** \\ \end{tabular} & \begin{tabular}{c} **Control** \\ **Model** \\ \end{tabular} & \begin{tabular}{c} **Merge** \\ **Change** \\ \end{tabular} & \begin{tabular}{c} **Lane** \\ **Change** \\ \end{tabular} & \
\begin{tabular}{c} **Coordination** \\ **Methodology and Advantage** \\ \end{tabular} &
\begin{tabular}{c} **Limitation** \\ \end{tabular} \\ \hline
[23] & Centralized & \begin{tabular}{c} ACC \\ MPC \\ \end{tabular} & ✓ & ✓ & & & \
\begin{tabular}{c} • Uses a mathematical-based scheme \\ Fast execution \\ \end{tabular} &
\begin{tabular}{c} • Not applied for resolving temporary traffic \\ bottleneck events \\ \end{tabular} \\ \hline
[24] & Centralized & MPC & ✓ & & & & \
\begin{tabular}{c} • MPC Longitudinal control \\ Supports multiple control operations \\ Supports collision avoidance \\ \end{tabular} &
\begin{tabular}{c} • Use for a platoon control only \\ Supports collision avoidance \\ \end{tabular} \\ \hline
[25] & Centralized & IDM & ✓ & ✓ & & & \
\begin{tabular}{c} • Supports inter-patoing control \\ Supports safe platoon merging \\ \end{tabular} &
\begin{tabular}{c} • Assumes perfect communications \\ \end{tabular} \\ \hline
[26] & Centralized & CACC & ✓ & ✓ & ✓ & & \
\begin{tabular}{c} • DSRC-based platoon management \\ Supports multi-platoon controls \\ \end{tabular} &
\begin{tabular}{c} • Not applied for resolving temporary traffic \\ bottleneck events \\ \end{tabular} \\ \hline
[27] & Centralized & CACC & ✓ & & & \
\begin{tabular}{c} • Heuristic platoon control model \\ Supports legacy networks \\ \end{tabular} &
\begin{tabular}{c} • Not traffic scheduling for congested areas \\ \end{tabular} \\ \hline
[28] & Decentralized & CACC & ✓ & & & \
\begin{tabular}{c} Multi-platoon control scheme \\ Supports quick recovery connectivity \\ \end{tabular} &
\begin{tabular}{c} • Not applied for resolving temporary traffic \\ bottleneck events \\ \end{tabular} \\ \hline
[29] & Decentralized & CACC & ✓ & ✓ & & \
\begin{tabular}{c} • Hybrid platoon control protocols \\ Highly efficient planning \\ \end{tabular} &
\begin{tabular}{c} • Not applied for resolving temporary traffic \\ bottleneck events \\ \end{tabular} \\ \hline
[30] & Decentralized & Wiedemann & & & & \
\begin{tabular}{c} • Closed-form analytical solution \\ Supports fast saving \\ Decentralized platoon control \\ \end{tabular} &
[31] & Decentralized & CACC & ✓ & ✓ & & \begin{tabular}{c} • Decentralized platoon control model \\ \end{tabular} & \begin{tabular}{c} • Not applied for resolving temporary traffic \\ bottleneck events \\ \end{tabular} \\ \hline Proposed & Decentralized & \begin{tabular}{c} ACC \\ CACC \\ \end{tabular} & ✓ & ✓ & ✓ & \
\begin{tabular}{c} • Coordinates multi-platooning system \\ Supports dynamic selection size \\ \end{tabular} &
\begin{tabular}{c} • Traffic type is homogeneous \\ Every vehicle must adopt the proposed algorithm to pass \\ through the congestion spot \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of related works. For decentralized approaches, [PERSON] et al. [28] proposed a decentralized platoon maintenance strategy in which a platoon vehicle needs to know its distance from its preceding vehicle to adjust its velocity. When a platoon vehicle joins or leaves the platoon, the new pair of preceding-behind vehicles need to exchange status information to adjust their velocity and distance. To accelerate such a process, the authors proposed computing the velocity, acceleration, and distance information in advance and storing them in the velocity profile. As a result, a vehicle can immediately adjust its velocity to achieve the minimum platoon gap distance without recalculation when there is a join or leave maneuver. [PERSON] et al. [29] used Bezier curves combined with CACC to plan the trajectory of platoon merging and manage platoon maneuvers, such as lane-changing and adjusting the gap distance between neighboring vehicles.