# Priority of Emergency Vehicle Dynamic Right-Of-Way Control Method in Networked Environment
## 3 Experimental Verification
### Simulation Experiments and Data Analysis
#### 3.2.2 Analysis of Experimental Results  
The experiment adopted a comparative analysis of control variables and conducted statistical analysis on the running time of vehicles under various traffic scenarios and input conditions. The traffic organization methodologies are as follows: (1) Equal right-of-way (ER)--CVs and EVs could drive in any lane and change lanes freely without intervention; (2) Priority for special road right-of-way (PSR)--the outer lane is a dedicated lane for EVs, so CVs are not allowed to enter that lane; (3) Dynamic right-of-way (PDR)--the outer lanes are virtual dedicated lanes for EVs so that CVs can enter intermittently. The experimental simulation inputs and output data are presented in Tables 4-7. Figure 10 depicts the experimental results under various CV flow conditions. Since the three test methods travel the same length of road, the shorter running time indicates that the vehicle is moving faster and more efficiently, where the length of the non-intrusion interval is \(L_{1}=15\) m, and the length of the buffer zone is \(L_{2}=90\) m. In all the presented curves, except for the PSR curve in Figure 10a, which remained unchanged, the other curves revealed an upward trend, but the degree was different. Under PSR conditions, since EVs and CVs drive in separate lanes, the operation of the EVs was not affected by the CVs, so the corresponding curve illustrates a flat trend. Obviously, the EV operation effect was remarkable under the PDR condition (Figure 10a), and it was almost close to the PSR operation effect when the flow rate was less than 1700 pcu/h. In Figure 10b, at flow rates less than 1800 pcu/h, the PDR had less impact on the CVs than the PSR, therein increasing the delay by less than 8% compared to ER. Both the PDR and ER methods were implemented without setting a dedicated lane, while the PSR method required a dedicated lane to be implemented. Combined with the analysis shown in Figure 10a,b, the proposed PDR method could significantly reduce the delay of the EV's operation. Given that the CVs' delays were almost unaffected (less than 8%), the maximum delay could be reduced \begin{table}
\begin{tabular}{c c c c c} \hline \(v_{min}\) & \(v_{max}\) & \(a_{max}\) & \(\tau\) & \(\Delta\theta\) \\ \hline
30 km/h & 50 km/h & 1.5 m/s\({}^{2}\) & 1000 ms & 200 ms \\ \hline \end{tabular}
\end{table} 
Table 3: Simulation parameter input value. by more than 80% (when the flow rate was 1600 pcu/h), and the conclusion was based on the relative performance of the PDR and ER methods. Figure 10a,b show that the PDR control effect under a high flow rate was more sensitive: the change with the flow rate was large, and the delay was too large. Figure 10a infers that, when the flow rate exceeded 1950 pcu/h, the EV's delay was greater than that of the ER method, thus indicating that the advantages of the PDR could no longer be reflected. Figure 10b highlights that, when the flow rate exceeded 1900 pcu/h, the CVs' delay under the PDR method increased sharply, again revealing that the PDR method was unsuitable for high flow conditions. In other words, the PDR approach cannot achieve satisfactory operating results on road sections with a saturation greater than 0.8. The above phenomenon was mainly due to the frequent lane change of the CVs owing to the PDR control method. Given that the CVs must avoid the EVs and change lanes in time, this lane change may destroy the original stable group of following vehicles in the inner lane, thus causing some vehicles to decelerate and even generate deceleration waves. As a result, the phenomenon illustrated in Figure 10a,b occurs in high-traffic situations. Figure 10: Effect of the CV flow on the running times of different vehicles: (**a**) EVs and (**b**) CVs. Figure 11 depicts the change curve vs. running time due to various buffer zone lengths in front of the EVs, which reflect the operating efficiency by the change in running time. The shorter the running time, the higher the efficiency when the length of the running section is the same.