陈东静
随着我国经济社会快速发展和人民生活质量的不断提高，城市人口不断增加，小汽车拥有率和使用率也在不断提高，给城市交通系统带来巨大压力。特殊需求是指交通需求处于特殊状态、交通供给处于特殊状态和交通运行环境处于特殊状态三种情形。由于日益丰富的城市生活，人们的各类交通需求急剧上升，造成道路随机扰动因素不断增多，大型活动、交通事故、占道施工、紧急交通等交通事件频繁发生；同时，气候变化带来恶劣天气的增多也使本就脆弱的交通系统面临更大的考验。
本文从现有特殊需求管控技术出发，首先将特殊需求分为大型活动、交通事故、占道施工、恶劣天气和紧急交通五类进行分类研究，对这些特殊需求给交通系统造成的影响进行深入分析；其次，详细阐析了特殊需求下的交通系统特征、交通拥挤特征、交通拥挤管控特征和交通拥挤管控关键技术，为提出有效的单点信号控制策略奠定了基础；再次，将单个交叉口的拥挤分为半拥挤、全拥挤不溢出和全拥挤有溢出三种拥挤状态，提出每种拥挤状态下拥挤交叉口信号控制策略的触发与结束条件，并研究分析了检测器的布设位置，提出双排队检测器的布设方法；最后，在对各类拥挤状态下信号控制策略进行综述的基础上，提出基于等排队强度的半拥挤信号控制策略、基于多目标优化的全拥挤不溢出信号控制策略和基于需求控制的全拥挤有溢出信号控制策略，并以北京市展南口交叉口及其邻近交叉口为例，利用VISSIM仿真软件对各种拥挤状态下的信号控制策略进行了仿真验证，仿真结果表明本文提出的信号控制策略具有良好效果。
关键词：特殊需求，单交叉口，信号配时，排队长度，理想点法
With China's rapid development in economic and social, the people's quality of life has been continuous improved, the city's population increased, car ownership and usage are also constantly improve, creating enormous pressure on the urban transport system. Special needs are three scenarios that traffic demand in a special state, traffic supply in a special state and traffic environment in a special state. As a result of the increasingly rich city life, people of all kinds of traffic demand has risen sharply, causing increasing road random disturbance factors, such as large-scale activities, traffic accident, construction of road occupation, emergency transportation, et al. The frequent occurring of these random disturbance factors creating enormous pressure on the urban transport system. At the same time, climate change has brought an increase in bad weather also makes the fragile transport system faces a greater challenge.
The paper start from the special events. First of all, special needs is divided into large-scale activities, traffic accidents, construction of road occupation, heavy weather and emergency transport five categories to classify research, and then this paper in-depth analysis of the impact that these special needs bring to the transportation system; Secondly, detailed analysis of the characteristics of the special needs of the transportation system, heavy traffic characteristics， congestion control features and Key Technologies of Congestion Management and Control, and laid the foundation for the proposed single point signal control strategy; Again, the crowded conditions of a single intersection is divided into three crowded state: half crowded, all crowded not overflow, all crowded and overflow. Then, this paper proposed the trigger and end conditions of intersection signal control strategy under each crowded state, analyzed the setting position of the detector, and double line detector layout method is put forward. Finally, on the basis of reviewing the various crowded state signal control strategy. This paper proposed half-crowded signal control strategy based on queuing strength, all crowded not overflow signal control strategy based on multi-objective optimization and all crowded and overflow signal control strategy based on demand control. At last, this paper takes the Zhannankou intersection and the adjacent intersections of Beijing as an example, and proposed a VISSIM simulation model to test the effect of each signal control strategy. The simulation results show that the proposed signal control strategy with good effect.
Key Words: special events, single intersection, signal timing, queue length, ideal point method
