基于活动的瓶颈模型和收费机制:研究进展评述

Vickrey于1969年应用确定性排队理论,首次提出了一个能导致所有出行者具有相同交通费用的内生出发时间选择模型,即著名的瓶颈模型.50年前,Vickrey提出的瓶颈模型以出行作为分析单位,没有考虑出行与活动之间的相互关联.近年来,出现的基于活动的瓶颈模型考虑了时变活动效用对通勤者出发时间选择的影响.瓶颈处的排队延误纯粹是一种社会损失,拥挤收费是消减瓶颈排队延误的有效的经济手段,而瓶颈模型是研究拥挤收费的强有力工具.本文回顾了瓶颈模型的研究进展,介绍了经典的瓶颈模型和基于活动的瓶颈模型的基础理论,分析和比较了两类模型最优动态收费和最优阶梯收费下的解及其消除排队延误的效率.     

随机动态交通网络中的停车行为

传统的静态确定型停车行为模型忽略了网络的时变性和随机性.基于道路供给和交通需求的不确定性,研究了随机动态交通网络中出行者的停车行为,建立了供需相互作用下的不动点拟动态停车行为模型,设计了基于Monte Carlo模拟方法的算法来求解该模型.算例结果表明,该模型能有效地模拟人们的停车选择行为.这一研究有助于加深对旅行行为的理解和透析交通行为的本质,为正确评价停车政策和合理规划停车系统提供了策略.     

Modeling an Elastic-Demand Bimodal Transport Network with Park-and-Ride Trips

This paper presents a network equilibrium formulation for modeling commuters＇ travel choices in a bimodal transport system with park-and-ride （P＆R） trips while the total demand is elastic to the congestion level of the network. A super-network approach is adopted in the proposed model. It is assumed that commuters＇ trips are categorized into two types, auto mode only and a combined mode with both auto and transit modes. The former is referred to as the pure mode trip and the latter as the P＆R mode trip. The proposed model simultaneously considers the commuter＇s choice of the pure mode versus the P＆R mode, the choice of parking location for the pure mode, the choice of transfer point for the P＆R mode, as well as the route choice for each mode. The demand elasticity of transport system, the capacity constraints of transport facilities, and the congestion interaction throughout the super-network are also explicitly incorporated into the proposed model. The results of the numerical experiment show the following key findings： （i） traditional parking/P＆R models may overestimate or underestimate travel demand distribution over network; （ii） parking/P＆R, transit scheduling, and carpooling schemes bring significant impacts on commuters＇ travel behavior and network performance; and （iii） different transport policies may be to some extent mutually substituted .     

天津滨海站轨道层高大模板支设技术

在建筑工程施工中,由于框架结构、框剪结构设计工艺的增多,对模板工程的应用也相应增大.该文结合在模板工程施工中问题,就高大模板支设施工技术进行探讨,从主体结构中各种施工重点和难点,给予详细的阐述,并就其工艺、要求、方法等,提出相应的措施,以提高高支模板工程的施工效率和安全性.     

非可加路径费用的交通网络平衡问题

利用变分不等式方法研究了非可加路径费用的交通网络平衡问题,给出了与平衡条件等价的变分不等式模型,它包含了可加路径费用的网络平衡模型.此外, 讨论了模型解的存在性和惟一性条件,这为进一步研究一般交通网络的用户平衡问题提供了条件.     

多中心城市系统均衡分析与轨道交通投资影响评价研究

考虑了私家车、公交车和地铁三种出行方式,基于连续型多项logit模型,假设居民选址偏好是异质的,探讨了线性多中心城市中居民住宅区位和工作地点的选址行为;通过比较引入轨道交通前后城市系统均衡状态,分析了轨道交通投资对居民分布、住房价格、不同商业中心对就业者吸引力的影响.结果表明轨道交通的引入使得劳动力更聚集于较发达的商业中心,进一步拉大了商业中心吸引力之间的差距;交通的改善导致居民向非中心区域迁徙,使得城市人口密度和住房价格分布更均匀,从而弱化了"地段"的概念.     

Optimization of Time-Varying Parking Charges and Parking Supply in Networks with Multiple User Classes and Multiple Parking Facilities

The optimization of parking charges and parking supply over the time of a day is an important problem in the design of transportation networks. This paper presents a bilevel model to determine the opti-mal time-varying parking charges and parking supply in road networks with multiple user classes and different types of parking facilities. The upper level of the model aims to maximize the network net benefit in response to the parking charges and parking supply, whereas the lower level is a time-dependent network equilibrium problem with elastic demand. A descent-gradient-based solution algorithm is adapted to solve the model. The numerical results show that the implementation of time-varying parking charges and parking supply is useful to effectively cater to the time-varying demand with different parking needs. The model provides a powerful tool for strategically designing parking locations and evaluating various parking policies.     

多目标路径诱导下平衡市场渗透率的确定

假定在多目标路径诱导下,用户基于旅行时间和旅行费用权衡的水平上做出路径抉择,这有别于传统的单目标路径诱导下,用户选择旅行时间最小的路径出行的决策.在先进的旅行者信息系统下,有诱导装置的出行者能更准确的选择旅行负效用最小的路径出行,而无诱导装置的出行者对出行路径的选择有更大的随机性,因此路径诱导能给出行者带来收益.假定路径诱导带来的收益决定了在路网达到平衡时有多大比例的出行者使用诱导装置,即平衡市场渗透率.本文利用混合网络随机用户均衡建模理论,研究了多目标路径诱导下平衡市场渗透率的确定方法,并设计了一个求解模型的算法.通过算例讨论了单目标和多目标路径诱导、旅行费用函数形式以及信息质量参数对平衡市场渗透率的影响.研究结果表明,与多目标路径诱导相比,单目标路径诱导可能低估或高估平衡市场渗透率;平衡市场渗透率随信息质量是递增的,但其边际影响是递减的.