利用GPS探偵車回報高速公路壅塞路段之系統設計

Abstract

提供用路人即時交通資訊，包含車速、車流量等資訊，可節省行車時間及能源消耗。由於具備各式感測器與無線資料傳輸的智慧型手機逐漸普及，利用在行駛車輛上的智慧型手機回報取得即時交通資訊成為可行的方式。傳統是利用探針車傳送旅行資訊，包括車速、車輛位置至交通資訊中心。然而，當探針車數量增加食，將有許多不必要的資訊回傳至交通資訊中心，增加通訊成本。本研究提出一個交通回報系統和監測高速公路上塞車狀況。交通資訊中心保存路段上塞車路段，包括塞車起始結束位置、所需旅行時間，並透過無線網路廣播給路上所有車輛。當探針車收到資訊後，比對收到廣播訊息和當前旅行路況變化。當兩者在塞車起始結束位置或旅行時間有巨大變化，探針車將此變化回報給交通資訊中心。依據這些回報，交通資訊中心更新其保存之資料，並且將這變化廣播告知用路人。為了分析系統效能，我們使用運輸模擬軟體VISSIM來進行實驗模擬。研究成果證實，我們所提出的方法能有效的偵測高速公路上塞車路段的變化，並且提前警告85%以上用路人即將在100公尺內遇到塞車。除此之外，此回報機制減少了超過50%的探針車和交通資訊中心間之通訊成本。

Providing real-time traffic information, such as traffic speed and travel time, to road users can save traveling time and reduce fuel consumption. With the increasing popularity of smartphones, which are embedded with a variety of sensors and capable of wireless data communication, smartphones on moving vehicles can be used as probes to collect real-time traffic information. Conventional probe vehicles send their traveling data including speed and location to a traffic information center (TIC) periodically. However, as the number of probes increases, there may be redundant reports sent to the TIC. In this thesis, we present a traffic report system and method to monitor the dynamic changes of traffic jams on highway. The TIC maintains the start location, end location and travel time of each traffic jam, and broadcasts the information to the probes, as well as the general road users. As the probes travel on the highway, they compare the broadcast traffic jams with their traveling data. If there are significant changes of the start location, end location or travel time are detected, the probes report the changes to the TIC. Based on the reports, the TIC updates the status of traffic jams and broadcasts the new traffic jam information. To evaluate the performance of our system, we have performed simulations using traffic model simulator VISSIM. The simulation results indicate that our approach can effective monitor the dynamic changes of traffic jams on highway and provides advance warning of traffic jams to over 85% of road users with location errors under 100 m. In addition, the report policy we proposed reduces over 50% of the communication between the probes and the TIC.