Capacity Analysis And Design Of Urban At-grade Signal Intersection

The problem of safety and efficiency for urban at-grade signal intersection has been the focus of academic research in recent years. The efficiency of intersection is usually measured with capacity and corresponding level of service. The capacity of intersection is mainly relative with signal timing, geometric characteristics of road and transport facilities, and traffic characteristics of intersection.By analyzing these areas, this paper aims to analyzing the complex traffic flow movement phenomenon, to explore the effective measures to improve the capacity, the level of service and the safety of at-grade signal intersection, to give the complicated signal intersection a more distinct looks.The pursuit of this paper is quantifiable and practical measures, not just the general talks of qualitative sense, meanwhile, getting rid of too pedantic and frightening formula analysis, attempting to provide some useful and easy operative strategy.By referring to latest version of the authoritative publication in every direction, based on the foreign and domestic experiences, to analyze comprehensively the space design of intersection, and provide a systematic and clear framework for the methods of signal timing and signal evaluation.First, from the point of the space design view, this paper studies the drainage design measures for intersection deeply, introduce design and improved measures for each component of the at-grade signal intersection, and provide several workable proposals and introduce several methods that is still not in China currently to effectively increase the capacity and safety. For instance, using the extending curbs to shorten the distance pedestrians crossing the street, and the bicycle lane will be placed on the left turn of the right-turn lane, and so on.Secondly, on the signal control, based on the foreign results of signal control research, this paper introduce systematically the types of signal control for intersection, and the proposal for which types should be selected, the process of signal timing, and methods of phase design. Because the turn left flow is the most important reason to cause the intersection conflict, this paper particular emphasis on the left phase design. The introduce of foreign experiences considering the actual traffic conditions of China, the recommendations can be implemented with nature. When the program for the signal control has already established, the next problem is whether the new program is really better than the old one, and if has several optional choices, which one of these is better. So, it is very important to evaluate and select the program. This paper systematically study the evaluation methods and evaluation level for the program of intersection signal control, and give a detailed overview of the current world's most popular HCM in particular.Moreover, the security considerations always run through this paper. The author intends to show the transportation student's respect for life.