外文翻譯--車輛檢測(cè)技術(shù)在交通管理上的應(yīng)用-交通線路-文庫(kù)吧資料
2025-05-22 05:49本頁(yè)面
【正文】 rious overhead detector technologies. Part 2 will provide field evaluation data and some general conclusions about detector performance and applications. Copies of the Final Report, a set of five pact disks containing the detector evaluation data, and other reports are available from the FHWA by writing to Mr. Pete Mills at HSR1, 6300 Georgetown Pike, McLean, VA 22101. Note: The detector performance data presented in this article were obtained by Dr. Klein when he was the project’s Principal Investigator at Hughes Aircraft Company. INTRODUCTION Maximizing the efficiency and capacity of the existing ground transportation work is made necessary by the continued increase in traffic volume and the limited construction of new highway facilities in urban, intercity, and rural areas. Smart street systems that contain traffic monitoring detectors, realtime adaptive signal control systems, and motorist munications media are being bined with freeway and highway surveillance and control systems to create smart corridors that increase the effectiveness of the transportation work. The infrastructure improvements and new technologies are, in turn, being integrated with munications and displays in smart cars and public access areas (such as shopping centers) to form intelligent transportation systems. Vehicle detectors are an integral part of these modern traffic control systems. The types of traffic flow data, as well as their reliability, consistency, accuracy, and precision, and the detector response time are some of the critical parameters to be evaluated when choosing a vehicle detector. These attributes bee even more important as the number of detectors proliferate and the realtime control aspects of ITS put a premium on the quantity and quality of traffic flow data, as well as the ease of data interpretation and integration into the existing traffic control system. Current vehicle detection is based predominantly on inductive loop detectors (ILDs) installed in the roadway subsurface. When properly installed and maintained, they can provide realtime data and a historical database against which to pare and evaluate more advanced detector systems. Alternative detector technologies being developed provide direct measurement of a wider variety of traffic parameters, such as density (vehicles per mile per lane), travel time, and vehicle turning movement. These advanced detectors supply more accurate data, parameters that are not directly measured with previous instruments, inputs to areawide surveillance and control of signalized intersections and freeways, and support of motorist information services. Furthermore, many of the advanced detector systems can be installed and maintained without disrupting traffic flow. The less obtrusive buried detectors will continue to find applications in the future, as for example, where aesthetic concerns are dominant or procedures are in place to monitor and repair malfunctioning units on a daily basis. Newer detectors with serial outputs currently require specific software to be written to interpret the traffic flow parameters embedded in the data stream. Since each detector manufacturer generally uses a proprietary serial protocol, each detector with a unique protocol requires corresponding soft
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