## 4 Numerical Simulations
### Experiments Design and Parameter Settings
However, for the CACC_Sine control strategy without the consideration of preceding vehicle switching, the longitudinal distance between vehicles M and A at the beginning of the LC-T stage, i.e., from 2 s to 5 s, is very slightly greater than 0 with a great risk of collision. As a result, vehicles M and A should make a greater speed adjustment as compared to the proposed CLC control strategy to ensure safety and catch up with their preceding vehicles quickly. Figures 14 and 15 also show that the acceleration and jerk of the CACC_Sine control strategy are more volatile as compared to  
Figure 14: The longitudinal accelerations of vehicles M and A of the two control strategies in scenario 2. (**a**) The proposed CLC control strategy, (**b**) CACC_Sine control strategy. Figure 12: The longitudinal speeds of vehicles B, M and A of the two control strategies in scenario 2. (**a**) The proposed CLC control strategy, (**b**) CACC_Sine control strategy. Figure 13: The Actual and Expected longitudinal distances between vehicles M, A and their preceding vehicles in two stages of the two control strategies in scenario 2. (**a**) The proposed CLC control strategy, (**b**) CACC_Sine control strategy. Figure 15: The longitudinal jerks of vehicles M and A of the two control strategies in scenario 2. (**a**) The proposed CLC control strategy, (**b**) CACC_Sine control strategy. In summary, the proposed CLC control strategy achieves smooth preceding vehicle switching of the controlled vehicles M and A during the lane-changing process. Please note that the smoother speed variations have a positive impact on traffic flow upstream of the target lane, this improving road mobility. In addition, less fluctuating acceleration and jerk effectively ensure the driving comfort. In order to analyze the improvement effect of the proposed CLC control strategy on the traffic flow of the target lane, some statistical indicators of the difference between the actual and expected motion states in the LC-T stage are analyzed for the above two lane-changing scenarios. Tables 2 and 3 show the statistical indicators of the difference between the actual and expected longitudinal distances and speeds of vehicles M, A, and their preceding vehicles in the LC-T stage for the two control strategies in two scenarios, respectively. The first three characters \"Avg\", \"Std\", and \"Max\" in all the indicators of all tables denote the average, standard deviation, and maximum, respectively. The last five characters \"DLD_M(A)\" and \"DLS_M(A)\" in Tables 2 and 3 denote the difference between the actual and the expected longitudinal distances and speeds of the vehicle M (A) and its preceding vehicle. It is evident that most of the indicators in the proposed CLC control strategy for longitudinal distance and speed tracking effects are obviously below that of the CACC_Sine control strategy. Although the average indicator of longitudinal distance tracking of the proposed CLC control strategy in scenario 1 is slightly better as compared to the CACC_Sine control strategy, its standard deviation and maximum are still better. It shows that the proposed CLC control strategy has better tracking control effects of vehicles M and A in the target lane during the LC-T stage and ensures a more stable car-following state. Tables 4 and 5 show the statistical indicators of longitudinal acceleration, i.e., \"LA_M(A)\", and longitudinal jerk, i.e., \"LJ_M(A)\", of vehicles M and A for the two control strategies in two scenarios, respectively. The results in Tables 4 and 5 show that the proposed CLC control strategy has significantly lower indicators as compared to the CACC_Sine control strategy except for the average longitudinal accelerations of vehicles M and A in two scenarios, and the average jerk of vehicle A in scenario 1. This further validates the conclusion obtained in Figures 9, 10, 14 and 15. The proposed CLC control strategy has more stable control inputs that greatly ensure the driving comfort.