A note on consistency of choice units in entropy models

In using entropy maximization models to forecast locational and travel behaviour, one is confronted with the problem of delineating the choice process as precisely as possible. In addition to defining a fine-grain choice structure implying individuals seeking distinct location sites within residential zones and travelling to distinct jobs or shops within destination zones, this note also accounts for the fact that the location choice is of a site for a household or firm, but the corresponding travel choices are by individual members of a household. In conjunction with disaggregation across quantities with large variance, the above principles are applied to formulate improved versions of residential and shopping location models.     

Workshop 1: Performance measurement and compliance

This workshop discussed challenges of measuring the performance of transport contracts, which is usually achieved by benchmarking the relevant services against a few key performance indicators (KPIs). Such KPIs (the workshop identified cost efficiency, service quality and safety/security as the top three) can be explicitly included in the contracts (with a focus on compliance) or can be rather informal and part of a trusting partnership. Limited availability of good data and appropriate information technology systems appear to be the greatest challenges within developed markets. In the context of creating a formal market (such as the South African taxi market), which encourages public transport measurement and compliance, our findings suggest that it is important to set as a first step minimum standards to address the backlog with respect to establishing performance measurement regimes.     

The impact of the application of new technology on public transport service provision and the passenger experience: A focus on implementation in Australia

The emergence of Intelligent Transport Systems (ITS) has been recognised with many initiatives during the last 20 years. In Europe, the “ITS Action Plan” identifies a number of applications as key elements contributing to the efficient co-ordination of the overall transport chain. The context and experience surrounding the recent widespread development of technological tools and ICT platforms to support the emergence of ITS are notable for the way in which they permeate the transport and logistics chain. But a key question remains: to what extent is the public transport sector able to exploit the wider benefits of ITS?     

The Sefton Coast Management Scheme: Project and Process

Abstract

The Sefton Coast Management Scheme in northwest England uses an area‐based project to achieve coordinated land management. It is founded on the ‘'Heritage Coast'’ model pioneered by the Countryside Commission where a ‘"Project Officer”; is employed to promote the Scheme and translate the aims into practical achievement. The Sefton Coast is described and a summary of British coastal planning policy precedes a detailed analysis of the Scheme. The Scheme is assessed with reference to practical management work, its success in competition for scarce financial resources, and the involvement of volunteers. It is established that the Project Officer is crucial to the success of the Scheme and that area‐based management can best be achieved through the local government planning process. Coastal planning needs now to be reviewed at national level to develop a policy for the whole coast using the experience of projects such as the Sefton Coast Management Scheme.     

Groups in DEA based cross-evaluation: An application to Asian container ports

In container port performance evaluation, a group of ports in one country is always significantly different from a group of ports in another country. This is noticed as the heterogeneity of port performance. It is therefore necessary to further investigate the impact of the different groups on efficiency evaluation of ports. The cross-evaluation method is a DEA extension tool to identify best performing DMUs and to rank DMUs using cross efficiency scores linked to all DMUs. A factor that possibly reduces the usefulness of the cross efficiency evaluation method is that cross efficiency scores may not be unique due to the presence of alternative optima. Doyle and Green 1 Doyle, J and Green, R. 1994. Efficiency and cross efficiency in DEA: Derivations, meanings and uses. Journal of the Operational Research Society, 45: 567–578. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] propose the use of secondary goals to deal with the non-uniqueness issue by the aggressive/benevolent model formulations. This article extends the model of Doyle and Green by considering the groups of DMUs in the determination of final cross efficiency. A new approach based on cross efficiency evaluation method is developed and applied to efficiency analysis of 28 container ports from 12 countries in Asia. A comparative study between traditional and newly proposed methods is conducted.     

Roadmap for free-floating bikeshare research and practice in North America

ABSTRACT

The deployment of smartphone-operated, non-station-based bicycle fleets (“dockless” or “free-floating” bikeshare) represents a new generation of bikesharing. Users locate bikes in these free-floating systems using Global Positioning Systems (GPS) and lock bikes in place at their destinations. In this paper, we review current free-floating bikesharing systems in North America and discuss priorities for future research and practice. Since launching in 2017, free-floating bikeshare has expanded rapidly to encompass 200+ systems operating 40,000+ bikes within 150+ cities. In contrast with previous systems, free-floating systems operate almost exclusively using commercial “for-profit” models, amidst concerns of financial sustainability. Governance for these systems is in early stages and can include operating fees, fleet size caps, safety requirements, parking restrictions, data sharing, and equity obligations. We identify research and practice gaps within the themes of usage, equity, sharing resources, business model, and context. While some existing bikesharing literature translates to free-floating systems, novel topics arise due to the ubiquity, fluidity, and business models of these new systems. Systems have numerous obstacles to overcome for long-term sustainability, including barriers common to station-based systems: limited supportive infrastructure, equity, theft or vandalism, and funding. Other unique obstacles arise in free-floating bikeshare around parking, sidewalk right of ways, varied bicycle types, and data sharing. This review offers background in and critical reflection on the rapidly evolving free-floating bikeshare landscape, including priorities for future research and practice. If concerns can be overcome, free-floating bikeshare may provide unprecedented opportunities to bypass congested streets, encourage physical activity, and support urban sustainability.     

Making Cycling Irresistible: Lessons from The Netherlands,Denmark and Germany

Abstract

This article shows how the Netherlands, Denmark and Germany have made bicycling a safe, convenient and practical way to get around their cities. The analysis relies on national aggregate data as well as case studies of large and small cities in each country. The key to achieving high levels of cycling appears to be the provision of separate cycling facilities along heavily travelled roads and at intersections, combined with traffic calming of most residential neighbourhoods. Extensive cycling rights of way in the Netherlands, Denmark and Germany are complemented by ample bike parking, full integration with public transport, comprehensive traffic education and training of both cyclists and motorists, and a wide range of promotional events intended to generate enthusiasm and wide public support for cycling. In addition to their many pro‐bike policies and programmes, the Netherlands, Denmark and Germany make driving expensive as well as inconvenient in central cities through a host of taxes and restrictions on car ownership, use and parking. Moreover, strict land‐use policies foster compact, mixed‐use developments that generate shorter and thus more bikeable trips. It is the coordinated implementation of this multi‐faceted, mutually reinforcing set of policies that best explains the success of these three countries in promoting cycling. For comparison, the article portrays the marginal status of cycling in the UK and the USA, where only about 1% of trips are by bike.     

ITS Solutions and Accident Risks: Prospective and Limitations

Abstract

This article investigates the prospective and limitations in the application of potential intelligent transport system (ITS) functions to reduce accident risks, using a cause‐treatment relationship. The main causes of road accidents are described and appropriate ITS solutions (including advanced driver assistance systems and advanced traveller information systems) are presented as countermeasures. Anticipated impacts are discussed and indicate that several ITS have the potential of improving road safety and addressing specific accident causes. However, attention is required on particular aspects of their implementation as they may trigger adverse effects by imposing behavioural adaptation risks, and overestimation and over‐reliance on system capabilities. Further, user acceptability and strategic implementation issues are paramount to the successful introduction of these systems.     

美国焊接桥梁的疲劳设计准则

50年前,疲劳设计在美国人看来并非是一个很严重的桥梁性能问题.疲劳设计运用了限制最大应力的概念,即假定疲劳极限发生在2×106次循环荷载时,利用最小应力与最大应力的比R,限制各点的最大应力.根据道路类型与每日平均车流量,采用型号为HS-20的设计车来测定特定周期.在20世纪60年代末至70年代初,发现钢结构桥梁中存在疲...     

Geographic information system design for network equilibrium-based travel demand models

Travel demand analyses are useful for transportation planning and policy development in a study area. However, travel demand modeling faces two obstacles. First, standard practice solves the four travel components (trip generation, trip distribution, modal split and network assignment) in a sequential manner. This can result in inconsistencies and non-convergence. Second, the data required are often complex and difficult to manage. Recent advances in formal methods for network equilibrium-based travel demand modeling and computational platforms for spatial data handling can overcome these obstacles. In this paper we report on the development of a prototype geographic information system (GIS) design to support network equilibrium-based travel demand models. The GIS design has several key features, including: (i) realistic representation of the multimodal transportation network, (ii) increased likelihood of database integrity after updates, (iii) effective user interfaces, and (iv) efficient implementation of network equilibrium solution algorithms.