A critical appraisal of the use of simple time-money trade-offs for appraisal value of travel time measures

Transportation - Stated choice surveys have established themselves as the preferred approach for value of travel time elicitation with the help of choice models. However, major differences exist in...     

The Role of Spatial Data Management Strategies in ICZM in Ireland

This article explores how a fresh approach to integrated coastal zone management (ICZM) in Ireland might be forged through the identification of a number of key innovative cross-sectoral professional initiatives and interdisciplinary academic thinking in this sector. It includes three interlinked research themes that assess existing cross-sectoral data management issues (to include an assessment of readiness for the INSPIRE and compliance with the Re-use of Public Sector Information European Union Directives), the degree of cross-pollination between the various sectors involved in managing the Irish Coastal Zone (to identify the need (or otherwise) for capacity- building to encourage cross-fertilization of ideas, skills, and knowledge exchange), and cross-professional competencies (to assess the desire/need (if any) for those working in coastal zone management to add to their existing competencies through continuous professional development or lifelong learning opportunities). Indeed, the specific competencies for coastal practitioners are identified here and these further illustrate the need for professional recognition of the role, responsibilities, and therefore the requirement for an appropriately qualified “Coastal Manager” professional, one that is seen not merely as a nicety but rather a necessity—a core enabler in any future innovative and integrative management approach.     

Synchronized Production and Transportation Planning Using Subcontracted Vehicles in a Production-Distribution Network

Abstract

Effective management of interfaces between procurement, supply, production and distribution for higher efficiency in the supply chain is an important issue in global manufacturing, where the synchronization of production and transportation planning represents important savings in operational costs. This paper focuses on the synchronization of production planning and transportation planning in a production distribution network, where transportation is subcontracted to a professional transportation enterprise (PTE) for vehicle-hiring. Dynamic and flexible numbers of vehicles are used to cater for fast changing market demands. Thus, the number of vehicles to be hired is viewed from the planning point of view as an operational decision considered simultaneously with production and transportation planning. A mathematical model – SPTP/MTDS – for synchronized production and transportation planning under multiple times and direct shipping strategy (MTDS) is discussed, and a Lagrange relaxation decomposition-based two layer decision procedure (LRD-TLDP) is developed. By introducing artificial decision variables and Lagrange multipliers, SPTP/MTDS is decomposed into a production decision sub-problem (SPTP-PD), and a distribution decision sub-problem (SPTP-DD). A priority-based assignment heuristic and a partial chain-based genetic algorithm are developed to solve SPTP-PD and SPTP-DD, respectively. An illustration of the application of the model in an electronic appliance manufacturing enterprise in China is presented.     

Getting the best of both worlds: a framework for combining disaggregate travel survey data and aggregate mobile phone data for trip generation modelling

Transportation - Traditional approaches to travel behaviour modelling primarily rely on household travel survey data, which is expensive to collect, resulting in small sample sizes and infrequent...     

Transportation — “Current on-board vehicle systems”

The paper reviews the current situation on-board microprocessor applications. It first describes the aspects of vehicle technology and performance that are the focus for on-board computing equipment, from engine management systems through to fully intergrated driver decision support. In the second section a wider perspective is taken by examining the interaction of the vehicle and its environment. The third and final section of the paper considers elements of communication which permit extensive transmission of vehicle and journey data for public and private use. The conclusion identifies factors which will influence the speed with which further applications will be adopted.     

The opening of the Amsterdam Ring Road

This paper presents the results of a major before-and-after study carried out to establish the short term effects of the removal of a severe bottleneck in the road network around Amsterdam. An important focus in the study was on measuring changes in the timing of travel, as well as changes in route choice, mode choice, destination choice and frequency of travel. The results of the study indicated that, in the short run, there was little or no change in mode choice, nor was there significant emergence of new induced trips. On the other hand, large shifts in time of travel as well as route choice were reported, emphasising the importance of alterations to the timing and routes of existing trips when congestion is relieved, and the need to consider the benefits these bring in evaluating the impact of any road investment.     

创新之桥——计量学在科学与技术中的应用——2010年世界计量日致词

<正>作为计量研究人员的快乐之一就是:计量学让我们走在科学的最前沿。我们总是试图了解,为什么大自然要限制我们去执行某种测量的能力。这种限制究竟是不可逾越的自然法则抑或是借助更睿智的思想便能攀越的藩篱。显然,这种智力挑战就是开拓新领域的动力。     

National policy towards cars: Singapore

Singapore has experienced rapid growth in car ownership, and private transport accounts for just under half of motorized trips in Singapore. Yet only since 1970 have determined efforts been made to curtail this increase. Simultaneously with this growth, Singapore's land‐use planners had called for the diversion of population growth into outlying residential estates while maintaining the central area's importance as an employment centre. The resulting anticipated concentration of commuter movement suggested a need for controls to restrain car ownership, reduce central‐area congestion and divert road users on to public transport. The policies followed are described. Those against ownership have included heavy road taxes and registration fees, with a system of discounts on the latter to discourage new purchasers except when replacing scrapped cars. Policies against car use include fuel taxes and the Area Licensing Scheme in the city centre, while parking space is also closely regulated. The measures adopted imply a goal of efficiency in promoting Singapore's planning objectives rather than environmental, safety or equity considerations, although the first two of these have lately received much more attention than formerly. The policies’ effect has been a temporary reversal in the growth of car ownership, but this growth has since resumed and recent further fee increases suggest a panic reaction rather than a coordinated strategy. Such coordination appears at present to be hampered by the fragmented administration of matters relating to transport. Other measures relating to car ownership and use in Singapore are also described.