Risk Management in Motorway PPP Projects: Empirical-based Guidelines

Abstract

This paper deals with the topic of risk management in Public Private Partnership (PPP). The analysis of the related literature reveals that risks must be analyzed and managed on a context-specific approach, and that there is a lack of a comprehensive study on the appropriate risk mitigation strategies for each risk embedded in PPP projects. Focusing on the transport sector, based on the results of a Delphi survey, the paper provides guidelines for both public and private parties in defining a list of significant risks in PPP motorway projects, and identifying for them both the effective allocation and the suitable mitigation strategies. Results of the Delphi survey have been compared with the common practices on risk management applied in eight real motorway PPP projects.     

Recognizing metro-bus transfers from smart card data

Transfer points between metro and bus services remain an elusive, yet critical junction for transportation practitioners. Based on massive Smart Card (SC) data, previous studies apply a one-size-fits-all criterion to discriminate between transfers. However, this is not sufficiently convincing for different transfer pairs. To counter this problem, this study applies an association rules algorithm and cluster analysis to recognize metro-to-bus transfers using SC data, and demonstrates transfer recognition in a case study based on SC data collected during a week in Nanjing, China. It is shown that 85% of the transfer-recognition results are quite stable through the whole week, and the median transfer time between metro and bus is below 20?min. The method proposed in this study can be used to identify the busiest transfer points and to obtain average transfer times, which facilitates a smarter and more efficient public transit network.     

案例教学法应用于政治理论课的实践与思考

案例教学法在思想政治理论课教学中的运用有利于学生树立正确的世界观、人生观和价值观,从而实现教学目的;有利于提高教学效果;有利于实现素质教育、培养创新型人才.案例教学法实施过程中应该处理好师生间的角色关系,教师是主导,学生是主体;应合理分配时间,处理好案例教学与理论讲授之间的关系;认识案例教学的局限性,处理好案例教学一般模式与特殊模式的关系.     

Exploring public bicycle network structure based on complex network theory and shortest path analysis: the public bicycle system in Yixing,China

A well-functioning public bicycle system relates not only to its mode of operation, vehicle allocation, rental station layout and vehicle leasing configuration, but also the bicycle network structure and its formation. However, the latter aspects have been widely overlooked in China. Here, we help to further attract more researchers to conduct relevant studies and make suggestions for the development of public bicycle transport in many small and medium-sized cities across the world. We demonstrate how to explore the public bicycle network structure of a county-level Chinese city – Yixing – known for its clay ware and tourism. We show that complex network theory and shortest path analysis technology are useful in characterizing the public bicycle network structure, in aspects such as network topology, the spatial distribution of sub-networks and traffic flows. Finally, the paper proposes relevant urban planning strategies.     

A method for solving the multi‐objective transit frequency optimization problem

Frequency setting takes place at the strategic and tactical planning stages of public transportation systems. The problem consists in determining the time interval between subsequent vehicles for a given set of lines, taking into account interests of users and operators. The result of this stage is considered as input at the operational level. In general, the problem faced by planners is how to distribute a given fleet of buses among a set of given lines. The corresponding decisions determine the frequency of each line, which impacts directly on the waiting time of the users and operator costs. In this work, we consider frequency setting as the problem of minimizing simultaneously users' total travel time and fleet size, which represents the interest of operators. There is a trade‐off between these two measures; therefore, we face a multi‐objective problem. We extend an existing single‐objective formulation to account explicitly for this trade‐off, and propose a Tabu Search solving method to handle efficiently this multi‐objective variant of the problem. The proposed methodology is then applied to a real medium‐sized problem instance, using data of Puerto Montt, Chile. We consider two data sets corresponding to morning‐peak and off‐peak periods. The results obtained show that the proposed methodology is able to improve the current solution in terms of total travel time and fleet size. In addition, the proposed method is able to efficiently suggest (in computational terms) different trade‐off solutions regarding the conflicting objectives of users and operators. Copyright © 2017 John Wiley & Sons, Ltd.     

浅谈港口建设项目设计阶段工程造价的控制方法

设计阶段的造价控制对整个工程投资的影响高达75％,故在设计阶段进行造价控制对港口建设项目总投资具有重要意义。介绍设计阶段进行方案优选、实行设计招投标制度、运用价值工程、实行限额设计以及设计监理等主动控制的基本方法,以合理地处理技术与经济之间的对立统一关系,达到节约总投资的目的。     

如何测设曲线上的直线桥

以北五公路一小桥为实例,详细介绍了曲线上直线桥的简捷测设方法,在公路桥梁施工测量中具有推广价值。     

PR系统中利用规划库建立、修正与更新规划假设

探讨了在规划识别系统中检索规划库内规划的方法，着重研究基于态势索引的检索问题。提出了基于事实及其属性的态势描述方法和建立状态库以便比较态势的相似性。此种方法适合于规划识别系统在初始情况下在规划库中找到较为完整的规划作为初始假设。还就在规划假设的确认、修正与更新中检索动作、动作序列和局部规划的方法进行了初步探讨。     

液压滑套式动力头用多轴箱特点及共CAD系统

本文对自行开发的多轴箱从结构特点上作了介绍,并对其配套的CAD系统的组成,功能及其中四轴设计单元的一带三算法作了介绍。     

视觉原理在公路设计中的应用

协调性是几何设计中的重要组成部分，它包括线形设计协调和外部景观环境的协调2个方面。从视觉原理出发，阐述了如何从线形设计的角度改善道路使用性能，并且提出了景观设置时需要注意的几个要点。