On the use of mathematical programming in the evaluation of transport policies

This paper focuses on the evaluation processes by which decisions regarding transportation alternatives can be assisted. A multidimensional approach usually called multiple criteria decision making is required to represent the complexity of transportation policy and systems.

The multiple criteria decision making techniques can be divided into two groups. The first is based on a ranking scheme approach and the second on a mathematical programming approach.

A multiple objective mathematical programming procedure known as Goal Programming is presented. The authors examined the use of that procedure in real transportation problems.

The results suggest that multiple objective mathematical programming techniques in general do not appear to be appropriate in transportation policy analysis involving mutually exclusive alternatives. Their use can be limited to special cases in the private sector.     

摩托车发动机凸轮测量测点布局优化设计方法

凸轮测量的目的不同,对测点间距的要求也不同;为了最大限度地减少测量工作量,把测量误差控制在允许范围之内,必须按公差要求进行凸轮测点布局;在实际测量中,应把计算出的测点间距间的角度值圆整为整数度;无论是用平面测头还是滚柱测头测量,按本文方法算出的测点间距与测量误差的平方根成正比,而与被测点的曲率半径的平方根成反比。     

Assessing the cost of transfer inconvenience in public transport systems: A case study of the London Underground

Few studies have adequately assessed the cost of transfers² in public transport systems, or provided useful guidance on transfer improvements, such as where to invest (which facility), how to invest (which aspect), and how much to invest (quantitative justification of the investment). This paper proposes a new method based on path choice,³ taking into account both the operator’s service supply and the customers’ subjective perceptions to assess transfer cost and to identify ways to reduce it. This method evaluates different transfer components (e.g., transfer walking, waiting, and penalty) with distinct policy solutions and differentiates between transfer stations and movements.The method is applied to one of the largest and most complex public transport systems in the world, the London Underground (LUL), with a focus on 17 major transfer stations and 303 transfer movements. This study confirms that transfers pose a significant cost to LUL, and that cost is distributed unevenly across stations and across platforms at a station. Transfer stations are perceived very differently by passengers in terms of their overall cost and composition. The case study suggests that a better understanding of transfer behavior and improvements to the transfer experience could significantly benefit public transport systems.     

The ‘Four Dimensions of Behaviour’ framework: a tool for characterising behaviours to help design better interventions

This paper sets out the rationale and structure of a tool for assisting policy-makers and practitioners to understand behavioural challenges and open up thinking on the design of effective ‘behaviour change’ interventions. The ‘Four Dimensions of Behaviour’ (4DB) framework is based on the theoretical and empirical research in a range of policy domains including transport and pro-environmental behaviour more generally. The 4DB framework characterises multifaceted behaviours along dimensions of actor, domain, durability and scope. Its application in workshop or structured settings opens up diverse and non-exclusive discussion on designing interventions to match salient behavioural characteristics. The use of the 4DB framework in the transport domain is demonstrated for travel behaviours of interest to policy-makers using examples of buying plug-in vehicles (PiVs), commuting by bicycle, eco-driving and making business trips by train.     

Activity patterns in space and time: calculating representative Hagerstrand trajectories

Daily activity diaries can be recorded as sequences of characters representing events and their contexts as they unfold during the day. Dynamic programming algorithms as used in bioinformatics have been used by a number of researchers to measure the similarities and differences between travel patterns on the basis of temporal sequencing of events, activity transition, and total activity time. The resultant similarity matrices have been shown to be more effective in classifying sequential patterns than classifications based on alternative similarity indices. The basic algorithms can be amended to include the geographic coordinates of events by a suitable amendment to the definition of distance. This permits quantitative classification of Hagerstrand-type activity trajectories on the basis of both activity and spatial similarity. Such a classification can be used to group similar trajectories and to identify representative trajectories that are analogous to measures of central tendency in univariate statistics, giving more concrete meaning to the concept of the activity pattern than any other method now available. The paper illustrates the effect of considering both events and locations in the classification of daily activity patterns using activity diary data gathered in the town of Reading. The algorithm has been implemented in the Clustal_TXY alignment software package.

Short range transit planning in Cairo

This paper describes an approach to short‐range planning that was developed to analyze and suggest improvements to the existing transit system serving metropolitan Cairo. The methodology is based on a corridor‐by‐corridor analysis which not only brings the scale of analysis down to a level which is necessary to address operational issues, but also results in a technology transfer strategy which allows the local planners to apply and test planning techniques in one corridor while more advanced techniques are developed for another. Procedures using the results of a system‐wide on‐board transit survey are developed to allocate the bus fleet to the existing bus network, identify new express services, and identify new direct services. Because the effectiveness of procedures used in short‐range transit planning depends on the existence of accurate data, and given the resources required for a large‐scale survey, the development of planning procedures based on a continuing monitoring program is also recommended. This paper concludes that although techniques using on‐board surveys are limited in their applicability, the corridor‐based approach to planning is sound.

     

A Review of the Evolution of Shared (Street) Space Concepts in Urban Environments

Abstract

This paper aims to clearly establish the origin and evolution of the shared space concept from a New Zealand perspective by reviewing the literature in the disciplines of both urban design and transportation engineering. The review process involves investigating the use and function of a public road space in the context of the changing of public expectations and how this can relate to a number of interconnected street design approaches (e.g. traffic calming and self-explaining roads (SERs)). These approaches have been used to minimise the influence of motor vehicles since the beginning of the automobile era. The shared space concept, when applied in public road environments in activity centres, has increasingly been embraced by urban planners, transportation engineers and regulatory agencies. A shared space diverges from a conventional road where all road users are encouraged to legitimately occupy the same road space with little physical separation. To achieve this in a safe and efficient manner, the design aims to reduce the dominance of the motor vehicle by promoting pedestrian and cycling activity and utilising the road space as a ‘place’ in addition to its ‘transport’ mobility and access purposes. Given the fundamental conceptual differentiation between a traffic-calmed street and a shared space, the paper argues that there are certain design elements, constituting a shared space, and without them, it would be difficult for a public street to function as a genuine shared space for all road users.     

轨道交通的产学研新模式——麻省理工学院/波多黎各地铁项目简介

波多黎各于20世纪90年代初才开始发展城市轨道交通,但因为善于利用后发优势,通过产学研的结合,充分考虑了地铁工程的多学科特性,走出一条有波多黎各特色的道路,成为美国和国际公共交通领域技术交流的典范.主要介绍了其产学研的项目,它由负责地铁项目的政府主管部门、波多黎各大学和美国麻省理工学院共同组织实施,历经地铁前期规划、修建、调试、运营和政策分析等全部过程,共13年的时间.这种方式提高了工程的质量和施工效率,推动当地轨道交通辅助产业的发展,加快了新技术的应用及研究,培养了一大批轨道交通的规划运营人才,为拉丁美洲城市轨道交通建设提供了一个新模式.波多黎各的经验对于我国当前的城市轨道交通建设同样具有借鉴意义.     

Geometric-based tyre vertical force estimation and stiffness parameterisation for automotive and unmanned vehicle applications

Advanced empirical, and physical-based tyre models have proven to be accurate for simulating tyre dynamics; however, these tyre models typically require expensive and intensive tyre parameterisation. Recent research into wheeled unmanned ground vehicles requiring vertical force analysis has shown good results using a simple linear spring model for the tyre which demonstrate the continued use for simple tyre models; however, parameterisation of the tyre still remains a challenge when load test equipment is not available. This paper presents a cost-effective tyre vertical stiffness parameterisation procedure using only measured tyre geometry and air pressure for applications where high-fidelity tyre models are unnecessary. Vertical forces calculated through an air volume optimisation approach are used to estimate tyre vertical stiffness. Nine tyres from the literature are compared to evaluate the performance of the vertical force estimation and stiffness parameterisation algorithms. Experimental results on a pair of ATV tyres are also presented.     

Welfare effects of congestion pricing in Singapore

This paper examines the Singapore Area License Scheme. Changes in scheduling and choices of transportation mode by commuters are discussed. Although the toll is shown to reduce travel times for many commuters, many commuters are shown to incur scheduling costs as a result of the toll. Using estimated parameters of an indirect utility function, welfare functions are computed to compare welfare levels prior to, and just after, the toll was put into place. The evidence suggests that the toll may have reduced welfare.