近幾十年來車輛急速的增加帶來大量的問題例如交通壅塞、事故和空氣汙染。交通資訊系統提供路況預估和事故偵測解決了上述問題。在車載網路中，路側單元扮演一個重要的角色，同時提供連線服務和收集車流資訊，交通資訊系統可以藉由路側單元蒐集的資料來進行路況分析。由於路側單元的建置成本昂貴以及有限的傳輸範圍，所以很難在各地佈署路側單元來為車輛達到無縫漫遊。
近幾年較少研究針對交通資訊系統進行路側單元佈署。在本篇論文中，首先定義交通資訊系統的效能以及發現系統中會產生資料重複問題，組中心佈署可以有效分散路側單元位置去避免上述問題。我們提出一個方法結合組中心概念以及車流量，最後透過實驗證明我們提出的方法可以有效地增加數據的品質及數量。

For decades, the number of vehicles increases fast. However, it brings many problems, such as traffic congestion, accident and air pollution. The traffic information system is proposed to solve the above problem. The system provides traffic prediction and accident detection services. Roadside unit (RSU) is an important component which provides access services and collects traffic flow data in Vehicular ad hoc network (VANET). Traffic system extracts useful information form RSUs and analyzes traffic state. Due to the high cost of RSUs deployment and the limited transmission coverage, it is difficult to deploy RSUs everywhere that provide seamless roaming for vehicles. In the past years, few RSU deployment strategies were proposed for traffic information system. In this paper, we first formulate the performance of traffic information system and discover data redundancy problem in the system. The group centrality deployment can effectively disperse RSUs location to avoid the problem. Second, we combine the group centrality concept and traffic flow then propose the enhance scheme. The extensive simulation results show that our proposed scheme increases the quality of data and the number of data.

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