應用N-Fi技術於高速公路計程收費機制之研究

Abstract

電子收費(Electronic Toll Collection, ETC)系統為ITS的主要項目之一，其內容為運用電子通訊技術取代人工，可有效提升作業效率，及改善擁擠與汙染等問題。國內於2006年正式啟用高速公路電子收費服務，並由遠通電收公司負責ETC系統之建置與營運，然該系統之運作制度無法達成計程收費之公平原則，技術架構也未能實現多車道自由流以及整合為ETTM系統之目標，乃迄今ETC運作成效不佳的主因之一；而回顧世界多國之電子收費系統案例，雖技術與營運架構各不相同，卻多為獨立之系統，其完整設施架構與通訊介面僅用於收費作業使用，實屬可惜，應設法將其結合更多資通訊功能，以提供整合性的ITS服務。 近場資訊系統(Near Field Informatics, N-Fi)為台灣大學土木所智慧型運輸系統實驗室所開之交通資訊平台，其應用構想係以近場無線通訊設備作為車輛於行程中接收與發送交通資訊之平台，以改善駕駛者受環境因素影響而錯失交通號誌標誌或可變資訊標誌訊息之問題，並可藉由車輛與路側端之通訊互動擷取車輛相關資訊與交通參數，達成車輛辨識系統或偵測器之功能。N-Fi系統之架構具備發展電子收費服務所需的基礎車路設施及通訊介面，目前已進入實際建置運作階段，可提供整合性的資訊蒐集與發佈之服務，惟就電子收費功能而言，目前尚無實際開發與測試之成果，如能就此議題加以研究，應具實用之價值。 為達成高速公路計程收費之公平目標，並整合電子收費與資訊服務，本研究依據國內ETC系統之建置規範研擬主線及匝道兩項計程收費機制，並以N-Fi系統架構實際建置軟硬體設備，於高速公路進行收費作業測試；實驗結果顯示，N-Fi技術於兩項機制下皆可正確執行收費作業，並可同時提供即時交通資訊發佈之服務。另為瞭解計程收費機制之運作效果，本研究以國道一號之實際路網及交通量資料進行模擬分析，結果顯示現行計次收費方式由於大量的短程旅次免費通行，確實有通行費短收之情形，每年最多將可能短收約5.6億之通行費金額，顯示落實計程收費之價值與必要性；而模擬結果亦顯示主線計程收費方式如能配合連鎖機制，可有效彌補通行費小數部份漏失及因系統作業失誤所產生之損失，乃最佳之收費機制方案，可供未來實際建置作為參考。

Electronic Toll Collection (ETC) system has been a main componet of ITS services, which applies advanced communication technologies in place of tranditional manual operations, aiming to increase the efficiency of toll collection works and reduce congestions as well as vehicle emissions at toll plaza areas. In Taiwan, ETC service has been available since 2006 and the system is currently operated by FETC. The framework of the system followed the original frequency-based toll collection type, which is still far from the equity of usercharge, and the adopted infrared technology also failed to achieve the goal of MLFF architecture and ETTM system. Near Field Informatics (N-Fi) system is a newly created platform for publishing and collecting real-time traffic information. Through the bidirectional communication between N-Fi OBU interface and road side beacons, drivers in enroute vehicles can directly receive electronic messages of traffic signs, signals or CMS around near field, and the beacons can also gather active information from vehicles and transmit which to traffic control center for further process. Currently the development of N-Fi system is already at the stage of construction and operation, providing the service of highway travel time prediction in Northern Taiwan. With the integrated infrastructure and communication interface, N-Fi system is having the potentiality for developing ETC function and all sorts of telematics services. In order to achieve both equity of usercharge and integrated driver information services, this research built two testing ETC systems based on N-Fi technology and ran real experiments at highway areas. Two types of distance-based highway toll collection schemes are designed and applied in the system, in which toll plazas are set at mainline and ramp respectively. The results of the experiments showed that the created systems are able to complete the operation of ETC and provide real-time information services under N-Fi framework. Furthermore, to analyze the effects of implementing the two schemes in real network, this research chose Freeway No.1 and use daily O-D data to run simulations. The results showed that current frequency-based toll collection type did occur toll loss since a large number of short-distance trips are using highway for free everyday, and the maximum loss may be up to 0.56 billion annually in comparison with distance-based toll collection types. The outcome of the analysis also showed that the presented mainline scheme with coordination mechanism is the optimal choise, which can effectively make up for the reduction of toll’s decimal parts and the loss from system error in the operation.