Marginal cost congestion pricing based on the network fundamental diagram

Congestion pricing schemes have been traditionally derived based on analytical representations of travel demand and traffic flows, such as in bottleneck models. A major limitation of these models, especially when applied to urban networks, is the inconsistency with traffic dynamics and related phenomena such as hysteresis and the capacity drop. In this study we propose a new method to derive time-varying tolling schemes using the concept of the Network Fundamental Diagram (NFD). The adopted method is based on marginal cost pricing, while it also enables to account realistically for the dynamics of large and heterogeneous traffic networks. We derive two alternative cordon tolls using network-aggregated traffic flow conditions: a step toll that neglects the spatial distribution of traffic by simply associating the marginal costs of any decrease in production within the NFD to the surplus of traffic; and a step toll that explicitly accounts for how network performance is also influenced by the spatial variance in a 3D-NFD. This pricing framework is implemented in the agent-based simulation model MATSim and applied to a case study of the city of Zurich. The tolling schemes are compared with a uniform toll, and they highlight how the inhomogeneous distribution of traffic may compromise the effectiveness of cordon tolls.     

Assessing the financial and social costs of public transport in differing operating environments and with endogenous demand

This paper uses a previously developed spreadsheet cost model which simulates public transport modes operated on a 12-km route to analyse the total costs of different passenger demand levels. The previous cost model was a very powerful tool to estimate the social and operator costs for different public transport technologies. However, as the model is strategic, some basic assumptions were made which are relaxed in this paper. First, the speed-flow equation in the original spreadsheet model assumes that speed decreases according to the ratio of the current frequency and the lane capacity which is based on the safety headway without taking into account passenger boardings. However, this may vary in different operating environments. Therefore, the speed-flow equation is improved by moving from a linear equation to a piecewise equation that considers the features of different operating environments. Second, the model assumes that supply is sufficient to meet demand. However, when the level of demand is high for the lower-capacity public transport technologies, passengers may find the incoming vehicle full and therefore, they have to wait more than one service interval. This paper applies queuing theory to investigate the probability of having to wait longer than the expected service headways which will affect the average passenger waiting time. The extra waiting time for each passenger is calculated and applied in the spreadsheet cost model. Third, the original model assumed that demand was externally fixed (exogenous). To evaluate the differences after applying these equations, endogenous demand rather than exogenous demand will be investigated by using the elasticities for passenger waiting time and journey time.     

Optimization of headways with stop‐skipping control: a case study of bus rapid transit system

Bus rapid transit system is designed to provide high‐quality and cost‐efficient passenger transportation services. In order to achieve this design objective, effective scheduling strategies are required. This research aims at improving the operation efficiency and service quality of a BRT system through integrated optimization of its service headways and stop‐skipping strategy. Based on cost analysis for both passengers and operation agencies, an optimization model is established. A genetic algorithms based algorithm and an application‐oriented solution method are developed. Beijing BRT Line 2 has been chosen as a case study, and the effectiveness of the optimal headways with stop‐skipping services under different demand levels has been analyzed. The results has shown that, at a certain demand level, the proposed operating strategy can be most advantageous for passengers with an accepted increase of operating costs, under which the optimum headway is between 3.5 and 5.5 min for stop‐skipping services during the morning peak hour depending on the demand with the provision of stop‐skipping services. The effectiveness of the optimal headways with stop‐skipping services is compared with those of existing headways and optimal headways without stop‐skipping services. The results show that operating strategies under the optimal headways with stop‐skipping services outperforms the other two operating strategies with respect to total costs and in‐vehicle time for passengers. Copyright © 2014 John Wiley & Sons, Ltd.     

基于综合H+T指数缩短租房人群通勤时间策略

通勤成本和住房成本随着与城市中心距离的变化,存在明显的消长关系。为便于讨论二者之间的互动关系,选择工作1~3年的租房人群作为研究对象。提出综合H+T指数计算方法,研究适合中国大城市租房人群的住房与通勤交通可支付能力指数取值,得出住房成本、交通经济成本、交通时间成本三者的推荐值。以此为规划约束目标,深入分析两种策略对不同收入租房人群通勤时间缩短的可能性:重新选择房源,缩短通勤距离,以增加住房成本为代价缩短通勤时间;住房不变,选择更快的交通工具,但交通经济成本有所上升。     

"双超"运输对重庆道路货运市场的影响

双超运输对道路货运市场的影响主要体现为变相增加市场运力、改变货运成本结构和扭曲货运市场运价,并由此导致了货运市场的无序,严重阻碍了货运市场健康持续发展。因此,坚持不懈地治理双超运输。整顿规范道路货运市场,既是道路货运行业可持续发展的需要,也是构建和谐交通的需要。     

关于公路施工企业最佳工程量以及成本利润分析

根据经济学的有关原理,结合公路施工企业的具体情况,建立模型,计算最佳工程量,可为公路施工企业决策提供一种思路。     

我国建筑工程计价模式与国际惯例对比分析

我国加入WTO之后,工程造价领域面临着尽快与国际接轨的强大压力,本文通过我国工程造价计价模式与国际上通用的英联邦国家计价模式的比较,探讨我国工程造价计价模式改革的途径。     

施工阶段公路工程造价的管理与控制

系统地介绍了施工阶段影响公路工程造价的各种因素,阐明了工程造价管理与控制的方法应措施。     

超载运输对道路货运成本及价格的影响

结合超载运输的实际情况,采用定性的分析方法．从货运成本的构成和价值规律入手,得出了合法运输和超载运输两种情况下的各种运输成本和边际成本的变化情况。以及运价持续低下的深层次原因,为治超采取相应措施提供参考依据。     

考虑集装箱流恢复的班轮运输船期恢复模型

为降低干扰事件对班轮运输服务的不良影响,本文研究了班轮运输中的船期干扰恢复问题.涉及4种船期恢复策略:调整航速、缩短在港时间、交换港口挂靠顺序和取消港口挂靠.当采取"取消港口挂靠"策略时,考虑集装箱流恢复问题,建立了船期恢复问题的混合整数非线性规划数学模型,并采用LINGO软件和遗传算法分别对模型进行求解.利用来自中远集装箱公司的实际案例,对模型和求解方法进行了验证,结果表明,所提模型和求解方法是正确有效的,能够为班轮公司提供科学的干扰管理决策支持.