隨著全球暖化造成的氣候異常，台灣受到氣候變遷的影響亦愈來愈明顯，使得台灣近年來天然災害頻傳，災情也愈來愈嚴重，為了在災害中搶救災民或傷患，相關緊急救援任務實為分秒必爭、刻不容緩的工作，因此如何使緊急救援車輛避開交通阻塞及道路崩壞區域，進而快速地到達災害現場便是極為重要之課題。
車用行動通訊網路 (Vehicular Ad-Hoc Network, VANET) 為智慧型運輸系統 (Intelligent Transportation System, ITS) 之一新興領域，VANET可讓車輛與車輛之間藉由Ad-Hoc 無線網路來彼此傳輸訊息，因此可以應用在行車安全及行車效率等交通管理之層面。而本研究主要目的乃為使用VANET即時整合模擬架構建立一緊急救援車輛管理機制，以縮短緊急救援車輛到達事故現場的時間，並分析車間通訊在疏散情境下對交通及通訊之影響。其中本研究開發之機制以動態路徑管理模組為主，研究中整合中觀車流模擬器DynaTAIWAN (Dynamic Traffic Assignment and Information in Wide Area Networks) 以及微觀網路模擬器NS2 (Network Simulation version 2) 兩模擬器，並讓裝有車機之混合車流可以透過車間通訊來傳遞交控中心之資訊，並在DynaTAIWAN內新增一緊急救援車輛模組，讓緊急救援車輛可在與路側設施通訊後，可獲得改良之A*演算法所求得之最短路徑。
本研究所開發之演算法使用方向性與路段車輛平均速度為啟發之評估函數，並在21節點路網與50節點路網上進行緊急救援車輛與疏散情境之實驗，以分析此動態路徑管理模組對緊急救援車輛之效用和車間通訊於疏散情境下各種因素對通訊品質之影響。實驗結果發現在不同路網上本研究使用之演算法較傳統之A*演算法穩定，且對緊急救援車輛之旅行時間與反應時間皆會有所改善，而在疏散情境下無需透過路側設施，僅靠車間通訊即有助於路網車輛之疏散。而由於通訊範圍與封包大小會影響通訊之品質，故採用適當之參數，可讓封包傳送次數與封包遞送率取得平衡，讓車輛可獲得即時交通資訊。

Duo to the climate anomalies caused by global warming, the impact of climate change on Taiwan has become increasingly significant, in recent years, it not only brings the more natural disasters affecting Taiwan, but also contributes to more severe consequences of those calamities. In order to rescue victims in time, all the relevant emergency responses are bound to be against the clock. Hence, how to dispose the emergency vehicles considering avoiding traffic jams and road collapse area, then reaching the incident site by a quick way is the most particularly important issue.
Vehicular Ad-Hoc Network (VANET) is one of the emerging fields of Intelligent Transportation Systems (ITS). VANET enables ad hoc wireless network between vehicles by transferring messages to each other. Therefore, it can be used to improve road traffic safety and efficiency of traffic management. The purpose of this study is to establish a real-time integration of the emergency vehicle management system under the VANET simulation framework. It can shorten the time of those emergency vehicles arrival time at the scene and analysis the influence of IVC (Inter-Vehicle Communication) on traffic and communication under evacuation scenario. In this study, we will focus on the dynamic routing module and integrate the traffic flow simulator DynaTAIWAN (Dynamic Traffic Assignment and Information in Wide Area Networks) with the network simulator NS2 (Network Simulation version 2) to build an emergency vehicles management system based on VANET. Besides, both systems can feedback real-time information between each other to simulate the various scenarios under VANET environment. And furthermore to construct a framework for emergency vehicle management system, we use the improved A* algorithm to shorten the times for emergency vehicles to arrive at accident sites. And let different types of vehicles which equipped with OBUs can transmit the real-time traffic information, and add an emergency vehicles module in DynaTAIWAN, allow emergency vehicles can communicate with the road side units, after emergency vehicles communicate with the road side units, it would get the shortest path road by using the directional and velocity modified to assess the function of the A* algorithm. Then this study select 21 nodes network and 50 nodes network to test this system, and the results show that the modified A* algorithm is fit for different road networks, the travel time and response time for emergency vehicles can be improved, it is also more stable than the traditional A* algorithm. This study also find out that even without road side facilities, inter-vehicle communication still can help vehicles to evacuate away from the network. In addition, the communication range and the packet size will affect the quality of communication, so if we use the appropriate parameters, vehicles will probably receive the real-time traffic information successfully.

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