封闭小区对城市路网交通流的影响机理及干预策略研究

Gated communities are gaining great popularity among urban planners and citizens because of their high security level and convenient management. However, their splitting influence on urban road network, which increases the trip distances, is one of the important factors contributing to traffic congestion. The gradual openness of gated communities helps to optimize road network structure and reduce traffic congestion. Up to now, there is still a lack of basic theoretical studies on the influence mechanism of gated communities on urban traffic flow and related intervention methods of gated communities. The traffic characteristics both inside and around the gated communities are analyzed, so as to build the traffic capacity model given to the interference of the community passageway and to determine correction coefficient. The capacity calculation model for dynamic road network taking the opening state into account is established to indicate the influence mechanism of gated communities on urban traffic flow and identify the bottleneck communities. The relationship between gated communities and urban road network is quantized in the aspects of road structure, service quality and environmental assessment, and the intervention strategies considering opening gated communities are brought forward. This study will provide theoretical support for gradual openness of gated communities and road network optimization. The solid foundation of theory and practice on road planning and traffic flow characteristics in the research group will do great favor to this project.

封闭小区以安全性高、便于管理等特点备受城市规划者和市民青睐。但其对城市路网的阻断作用，导致交通出行绕行距离增加，是造成相关区域交通压力增大、交通拥堵严重的重要原因之一。逐步开放封闭小区对优化城市路网结构、缓解交通拥堵具有重要意义。目前在封闭小区对路网交通流影响机理及与之相关的交通干预方法方面还缺少基础理论研究。本项目拟通过分析封闭小区内部及其周边交通特性，构建封闭小区出入口对路段通行能力影响模型，确定通行能力的小区出入口修正系数；以考虑小区开闭状态的动态路网容量计算模型构建为基础，揭示封闭小区对路网交通流的影响机理，识别交通瓶颈小区；从路网结构、服务质量及环境影响三方面量化封闭小区与城市路网互动关系，提出考虑开放封闭小区的交通干预策略。研究成果可为逐步开放封闭小区、优化路网结构提供理论依据。项目组在道路网规划理论与方法、交通流特性分析等方面具有较坚实的理论和实践基础，具备完成项目研究条件。

国内城市交通拥堵问题日益突出，交通供需结构失衡是根本原因。大型封闭小区在一定程度上破坏了城市路网结构进而影响到城市交通供给。其对城市城市交通的影响主要体现在：增加了机动车和行人的绕行距离，小区出入口路段易形成交通瓶颈，不利于破解公交“最后一公里”的问题。已有研究主要从封闭小区对城市政治、经济、社会和文化的影响等方面进行了定性分析，对封闭小区如何影响城市交通的量化研究较少。本研究拓展了封闭小区的内涵，梳理了封闭小区内部路网的主要布局形式和道路类型，总结了封闭小区的总体特征；建立了封闭小区出入口通行能力模型、考虑封闭小区出入口干扰的路段通行能力修正模型、考虑小区开闭状态的城市动态路网容量计算模型及封闭小区是否开放的识别模型，揭示了封闭小区对城市路网交通流的影响机理；构建了基于路网运行效率最大化和环境影响最小化为目标函数的区域路网结构双目标优化模型，量化了封闭小区开放与区域交通运行的相互影响；提出了居民小区、大学校园等典型封闭小区的开放改造方案，从区域路网结构优化、交通出行限制等方面提出了小区开放后的交通干预策略，初步建立了针对封闭小区的交通干预措施方法库。本项目研究成果初步建立了封闭小区交通影响及开放理论体系框架，完善了道路通行能力分析方法，丰富了交通流理论体系，能够为考虑开放封闭小区的路网结构优化、街区制推广等提供理论依据，对丰富和完善交通规划、组织和管理技术体系，缓解城市交通拥堵具有一定的应用价值。