# Priority of Emergency Vehicle Dynamic Right-Of-Way Control Method in Networked Environment
###### Abstract  
This paper proposes a dynamic right-of-way priority control approach for emergency vehicles (PDR-EVs) to improve their efficiency on basic road sections in the city based on a cooperative vehicle infrastructure system. Specifically, a movable physical function area was set in front of the EVs to prohibit connected vehicles (CVs) from entering a lane or to request them to change lanes to avoid a collision. Setting up a dynamic monitoring area at the EV's front end affords real-time monitoring of the CV's headway distribution in the inner lane. Moreover, a lane change request is sent when the CVs enter the buffer area, and the traversal search method predicts the optimal time and rate of speed to change the lane change and guides the CVs ahead of the EVs to merge into the target gap. Extensive simulations using the SUMO platform revealed that the priority of the dynamic right-of-way (PDR) control method reduced the average delay of the EVs by more than 70%, given that the road saturation did not exceed 0.8 and hardly increased the delay of the CVs (not more than 8%). Moreover, the simulations revealed that the long buffer area was suitable for low-volume conditions, and the short one was suitable for high-volume conditions. The proposed methodology fully employs the road space resources and enhances the EV's operating efficiency on basic road sections while considering the CV's operating efficiency. intelligent transportation; emergency priority control; dynamic right-of-way; intelligent connected vehicles (CVs); vehicle infrastructure cooperation +
Footnote †: journal: Applied Sciences  
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Footnote 1: email: _Applied_  
Footnote †: journal: Applied Sciences  
variable message sign (VMS) [8] and employs the entrance's variable guidance function to clear the target lane [9]. Given the vehicle infrastructure cooperation scheme, CVs are perceived and guided to enter the designated empty target lane without stopping and pass through the intersection [10]. Regarding road section priority, most studies focus on public transport vehicles. For instance, [PERSON] et al. [11] explored the time-division multiplexing of exclusive right-of-way, but this methodology significantly impacts regular traffic and does not improve the overall service level of the transportation system. [PERSON] et al. [12] extended the principle of intermittent bus lanes to road sections, thus reducing the impact of regular traffic on the operation of bus vehicles, but did not specify a specific control approach. [PERSON] et al. [13] and [PERSON] et al. [14] exploited the communication characteristics of autonomous driving by mixing CVs and bus vehicles on the BRT bus lane. They proposed a control strategy for CVs that utilized a virtual dedicated lane. Considering that CV queuing affects the running speed of public transport vehicles, [PERSON] and [PERSON] [15] proposed a moving bottleneck method based on the traffic wave theory to analyze the running conditions of public transport vehicles to reduce system-generated delays. In conclusion, existing investigations have not adequately investigated the right-of-way space of the road segment, and, therefore, the EV's operating efficiency on the road segment cannot be guaranteed. The different priority control methods are shown in Table 1.  
The conventional right-of-way time priority uses traffic information collection devices for EV vehicle information collection. However, the timeliness and accuracy of information collection cannot be guaranteed, and equipment maintenance costs are also higher. The intelligent and connected technologies that have been developed in recent years are also used in signal priority control, thereby enabling the ability to acquire road and vehicle conditions more accurately than traditional technologies, which allow for timely adjustments.